Electro-optically inspecting and determining internal properties and characteristics of a longitudinally moving rod of material

ABSTRACT

Electro-optically inspecting a longitudinally moving rod of material ( 12 ). Guiding rod ( 12 ) along its longitudinal axis by rod guiding unit ( 14 ), along optical path ( 20 ) within transparent passageway ( 22 ). Optical path ( 20 ) and transparent passageway ( 22 ) coaxially extend along longitudinal axis of rod ( 12 ) and pass through an electro-optical transmission module ( 24 ). Focused beam ( 28 ) from illumination unit ( 26 ) is transmitted through first side ( 30 ) of transparent passageway ( 22 ) and incident upon rod ( 12 ) within transparent passageway ( 22 ). Illuminating volumetric segment ( 34 ) of rod ( 12 ) by incident beam ( 32 ), such that incident beam ( 32 ) is affected by and transmitted through volumetric segment ( 34 ) and transmitted through second side ( 36 ) of transparent passageway ( 22 ), for forming rod material transmitted beam ( 38 ). Detecting transmitted beam ( 38 ) by detection unit ( 40 ), for forming rod material volumetric segment transmitted beam useable for determining internal properties and characteristics of rod of material ( 12 ).

RELATED PATENT APPLICATION

This application is a National Phase Application of PCT/IL03/00688having International Filing Date of 19 Aug. 2003, which claims priorityfrom U.S. Provisional Patent Application No. 60/404,144 filed 19 Aug.2002.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to using electro-optics for inspecting anddetermining internal properties and characteristics of a longitudinallymoving rod of material, and more particularly, to a method and devicefor electro-optically inspecting and determining internal properties andcharacteristics, such as density, structure, defects, and impurities,and variabilities thereof, of a longitudinally moving rod of material.The rod of material is continuously or intermittently moving along itslongitudinal axis while at least one focused beam of electromagneticradiation is incident upon, measurably affected by, and transmittedthrough, volumetric segments of the longitudinally moving rod ofmaterial, along with detecting the transmitted electromagnetic radiationbeam, during the electro-optical inspection process of measuring andanalyzing the internal properties and characteristics of thelongitudinally moving rod of material. The present invention isgenerally applicable for inspecting and determining internal propertiesand characteristics of a variety of different types of a rod ofmaterial, as long as the rod of material exhibits the behavior that anincident focused beam of electromagnetic radiation, while not alteringthe rod of material, is affected by and transmittable through volumetricsegments of the rod of material. For example, but not limited to, acigarette rod consisting of processed tobacco inside a rolled and sealedtube of cigarette wrapping paper.

The present invention is particularly applicable to that stage of anoverall commercial manufacturing sequence involving continuouslytransporting or conveying a rod of material between manufacturingprocesses. There exist overall commercial manufacturing sequencesincluding a stage whereby raw or initially processed material exiting anupstream manufacturing process is formed into a short discrete or longcontinuous rod of material, which is either wrapped inside a wrappingmaterial or is left unwrapped, and continuously transported or conveyedprior to entering further downstream processes, including for example, arod cutting process, eventually leading to production of bulk quantitiesof individually wrapped or unwrapped consumer product. For example, inthe case of manufacturing cigarettes, as part of an overall commercialmanufacturing sequence, bulk quantities of cut and processed tobaccoleaves, along with any number of cigarette tobacco additives oringredients, exiting an upstream manufacturing process are rolled,wrapped, and sealed, inside cigarette wrapping paper, and continuouslytransported or conveyed as long, narrow, continuous tobacco filledcylinders or rods prior to entering further downstream processes,including for example, a cigarette rod cutting process, eventuallyleading to production of bulk quantities of individually cut, wrapped,and non-filtered or filtered, cigarettes in a box.

During such a manufacturing sequence, internal properties andcharacteristics, such as density, structure, defects, impurities, andvariabilities thereof, of the continuously moving rod of materialexiting an upstream manufacturing process, may feature values outside ofacceptable ranges and/or may undesirably change prior to entering adownstream manufacturing process. At this stage of such a manufacturingsequence, it is critically important that these internal properties andcharacteristics of the continuously moving rod of material be determinedand monitored, such as by employing quality control and qualityassurance procedures, and subsequently controlled, such as by employingprocess control and process feedback procedures, prior to thecontinuously moving rod of material entering further downstreamprocesses or storage, in order to assure proper characteristics andperformance of the finished end products.

In particular, if one or more of the above indicated internal propertiesand characteristics of a given portion or section of the continuouslymoving rod of material is outside of established quality control orquality assurance values, use of such portion or section of the rod ofmaterial is expected to lead to downstream intermediate products, orstored rod of material, similarly failing their established qualitycontrol values, potentially causing undesirable rejection of material,manufacturing down time and added cost to the overall manufacturingsequence. For example, in the case of manufacturing cigarettes, if oneor more of the above indicated internal properties and characteristicsof a given portion or section of the rod shaped wrapped cigarettetobacco are outside of established quality control values, at least thatportion or section of the tobacco filled rod needs to be removed priorto entering further downstream processes or storage, otherwise, ‘belowquality’ cigarettes may end up in the consumer marketplace, clearlyundesirable to a cigarette manufacturer, as well as undesirable toconsumers of cigarettes.

Herein, internal properties and characteristics, such as density,structure, defects, and impurities, and variabilities thereof, of alongitudinally moving rod of material refer to the global, bulk, ormacroscopic, internal properties and characteristics, such as density,structure, defects, and impurities, and variabilities thereof, of aspecified volumetric segment or number of volumetric segments of thematerial, including bulk or macroscopic volume occupied by air andmoisture throughout the material, making up or forming thelongitudinally moving rod of material. These internal properties andcharacteristics of the longitudinally moving rod are to be clearlydistinguished from the local, molecular, or microscopic, properties andcharacteristics, such as molecular density, molecular structure,microscopic defects, and microscopic impurities, and variabilitiesthereof, of only the material, excluding bulk or macroscopic volumeoccupied by air and moisture, making up or forming the longitudinallymoving rod of material.

For example, internal properties and characteristics, such as density,structure, defects, and impurities, and variabilities thereof, of alongitudinally moving cigarette rod consisting of processed tobaccoinside a rolled and sealed tube of cigarette wrapping paper, refer tothe global, bulk, or macroscopic, density, structure, defects, andimpurities, and variabilities thereof, of a specified volumetric segmentor number of volumetric segments of the processed tobacco, includingbulk or macroscopic volume occupied by air and moisture throughout theprocessed tobacco, inside the rolled and sealed tube of cigarettewrapping paper. These internal properties and characteristics of thelongitudinally moving cigarette rod are to be clearly distinguished fromthe molecular density, molecular structure, microscopic defects, andmicroscopic impurities, and variabilities thereof, of only the processedtobacco molecules, excluding bulk or macroscopic volume occupied by airand moisture, making up or forming the longitudinally moving cigaretterod.

There is an extensive amount of prior art teachings of methods, devices,and systems, for electro-optically inspecting and determining ‘external’(and not ‘internal’) properties and characteristics, such as uniformity,structure, color, print, closures, openings, defects (for example,holes, defective and/or missing components), and impurities, andvariabilities thereof, of or on the ‘outer or exposed surfaces’ (and notof or in a specified ‘volumetric segment’ or number of ‘volumetricsegments’) of a plurality of continuously or intermittently moving rodsof material, where the rods of material are continuously orintermittently moving sideways along or rolling around their ‘radial’axes (and not moving along their ‘longitudinal’ axes) during the actualelectro-optical inspection process, as part of a commercial productionor manufacturing sequence.

The majority of such prior art is especially with regard toelectro-optically inspecting and determining properties andcharacteristics, such as uniformity, structure, color, print, closures,openings, defects (for example, holes, defective and/or missingcomponents, such as a defective or missing filter), and impurities, ofthe outer or exposed surface, for example, of the wrapping paper, of theopen end, and/or of the filter end, (and not of a specified volumetricsegment or number of volumetric segments) of continuously orintermittently moving individually cut and complete cigarettes in theirfinal form prior to packaging, moving sideways along or rolling aroundtheir radial axes. Such prior art is based on generating, detecting(collecting and measuring), and analyzing, light ‘reflected by’ (and nottransmitted through) the outer or exposed surfaces of the continuouslyor intermittently moving rods of material. Such prior art may be dividedinto two main categories, according to the type of optics, electronics,and/or electro-optics, employed during the electro-optical inspection.

In the first main category, electro-optical inspecting is performed bygenerating, detecting (collecting and measuring), and analyzing, lightreflected by the outer or exposed surface of at least a part of each rodof material, in the form of light beams or rays and intensities thereof.Selected examples of this main category of prior art, especially asapplied to electro-optically inspecting the outer or exposed surface ofat least a part of individual completed cigarettes, are the disclosuresof U.S. Pat. No. 3,980,567 to Benini; U.S. Pat. No. 4,090,794 to Benini;and U.S. Pat. No. 4,639,592 to Heitmann.

In the second main category, electro-optical inspecting is performed bygenerating, detecting (collecting and measuring), and analyzing, lightreflected by the outer or exposed surface of at least a part of each rodof material, in the form of photographic or video camera images.Selected examples of this main category of prior art, especially asapplied to electro-optically inspecting the outer or exposed surface ofat least a part of individual completed cigarettes, are the disclosuresof U.S. Pat. No. 5,013,905 to Neri; U.S. Pat. No. 5,228,462 to Osmalovet al.; U.S. Pat. No. 5,432,600 to Grollimund et al.; and U.S. Pat. No.5,448,365 to Grollimund et al.

The present invention is directed to commercial applications requiringreal time, non-invasive, high speed, high sensitivity, low noise, highaccuracy, high precision, temperature compensative, and low vibration,measuring and analyzing internal properties and characteristics, such asdensity, structure, defects, and impurities, and variabilities thereof,of a specified volumetric segment or number of volumetric segments, of arod of material, such as a cigarette rod, continuously or intermittentlymoving along its longitudinal axis, as the rod of material istransported or conveyed during a commercial manufacturing sequence,particularly a manufacturing sequence including quality control and/orquality assurance processes.

Accordingly, each of the above cited prior art, and similar prior art,feature at least two significant and fundamental differences, andassociated limitations thereof, with regard to the intended scope andapplications of the present invention.

The first significant and fundamental difference is that such prior artteaches about electro-optically inspecting and determining only‘external’ properties and characteristics, such as uniformity,structure, color, print, closure, defects, and impurities, andvariabilities thereof, of the outer or exposed surfaces of a pluralityof continuously or intermittently moving rods of material. Accordingly,such prior art teachings are solely based on generating, detecting(collecting and measuring), and analyzing, light ‘reflected by’, and not‘transmitted through’, the outer or exposed surfaces of the continuouslyor intermittently moving rods of material. Such prior art teachings arenot obviously extendable and/or applicable for generating, detecting(collecting and measuring), and analyzing, light transmitted through theouter or exposed surfaces of the moving rods of material, and therefore,are not obviously extendable and/or applicable for electro-opticallymeasuring and analyzing ‘internal’ properties and characteristics, suchas density, structure, defects, and impurities, and variabilitiesthereof, of a specified volumetric segment or number of volumetricsegments of the material making up or forming a longitudinally movingrod of material, according to the intended scope and applications of thepresent invention.

The second significant and fundamental difference is that such prior artteaches about electro-optically inspecting and determining the externalproperties and characteristics of the outer or exposed surfaces ofcontinuously or intermittently moving rods of material, where the rodsof material are specifically restricted to moving sideways along orrolling around their ‘radial’ axes, and not moving along their‘longitudinal’ axes, during the actual electro-optical inspection, asthe rods of material are transported or conveyed during a manufacturingprocess. Therein is no teaching about performing the electro-opticalinspection while the rods of material are moving along theirlongitudinal axes, during the real time electro-optical inspection, asthe rods of material are transported or conveyed during a manufacturingsequence. There are commercial manufacturing sequences which eitherrequire, or where it would be highly desirable and advantageous, havinga rod of material moving along its longitudinal axis, as the rod ofmaterial is transported or conveyed during the manufacturing sequence.

There are prior art teachings about electro-optically inspecting alongitudinally moving rod of material, as the rod of material istransported or conveyed during a commercial manufacturing sequence. Suchprior art, particularly applicable to the cigarette manufacturingindustry, selections of which are briefly described herein below, isalso fundamentally different from, and features significant limitationswith respect to, the intended scope and applications of the presentinvention.

In the disclosures of U.S. Pat. No. 6,213,128 B1, and U.S. PatentApplication No. 2001/0001390 A1, both to Smith et al., there aredescribed a method and apparatus for making and electro-opticallyinspecting a multi-component cigarette. As for the above previouslycited prior art, the electro-optical inspection is based on generating,detecting (collecting and measuring), and analyzing, light ‘reflectedby’, and not ‘transmitted through’, the outer or exposed surfaces of avariety of cigarette components, such as cigarette tobacco rods,filters, tubes, and chambers, in the form of camera images, as thesecigarette components are longitudinally resting or positioned on opencigarette wrapping paper which is continuously moving along itslongitudinal axis and transported or conveyed during the manufacturingsequence.

In the disclosures of U.S. Pat. No. 3,854,587; its reissue, Re. 29,839;and its improvement, U.S. Pat. No. 4,208,578, each to McLoughlin et al.,there are described an “(electro-)optical inspection apparatus formonitoring a continuously (longitudinally) moving rod (in particular, acigarette rod), comprising a circular head through which the rod passes(along its longitudinal axis), a first set of fiber optic conductorswhich transmits light from a source to the head to illuminate the rod,and a second set of fiber optic conductors which pick up light reflectedfrom (and not transmitted through) the rod passing through the head andtransmits the reflected light to a number of photoelectric elements. Thesecond set of conductors are divided into angularly spaced groups aroundthe head and adjacent groups lead to separate photoelectric elements”.Outputs of the photoelectric elements are processed and analyzed bylogic circuitry for determining the presence of a fault in the inspectedrod, and if found, causes a fault signal to actuate a rejectionmechanism when the part of the rod at which the fault has been sensedreaches a rejection point.

In the disclosure of U.S. Pat. No. 4,377,743 to Bolt et al., there isdescribed a device and corresponding method for electro-opticallyinspecting a longitudinally moving rod (in particular, a cigarette rod),wherein the device comprises “a plurality of focused lightemitter-detector units spaced circumferentially around a rod beinginspected, each unit being arranged to propagate focused light onto adefined surface region of the rod and to receive the light reflectedfrom (and not transmitted by) that surface region and further arrangedto generate an electrical signal related to the intensity of thereceived light. Two, or more, axially displaced arrays of units are eacharranged to inspect areas of the rod which are staggered in relation tothe areas inspected by the other array or arrays”.

In the Bolt et al. invention, “the measuring head of the apparatuscomprises a plurality of infra-red sensor units, which each contain alight emitting diode and a phototransistor, positioned behind respectivelenses. The lens for the light emitting diode focuses light onto aspecific area of the cigarette rod and the lens for the phototransistorcollects the light reflected from that area, i.e., “focuses” thereflected light onto the phototransistor”. Outputs of thephototransistors are processed and analyzed for determining the presenceof a fault in the inspected cigarette rod, and if found, causes a faultsignal to actuate a cigarette ejection mechanism. The invention includes“means (a transparent tube) for guiding the continuous cigarette rod(along its longitudinal axis) along a predetermined path extendingthrough an (electro-optical) inspection station”.

In the disclosure of U.S. Pat. No. 4,645,921 to Heitmann et al., thereis described an “Apparatus for optically scanning a (longitudinally)moving cigarette rod (a plurality of discrete, coaxial completecigarettes, long continuous cigarette rods, filter rod sections, and thelike) for the presence of defects in its external surface (and notinternal volume) which has two annularly arranged groups of diodes whichemit green light in the wavelength range of between 0.49 and 0.58.mu.and direct such light from the opposite sides of a plane that is normalto the (longitudinally) moving rod so that the incident light isreflected (and not transmitted) by successive annular portions of theexternal surface of the rod into the aforementioned plane. The reflectedlight is focused by systems of lenses upon discrete photosensitivetransducers through discrete slit diaphragms on the transducersthemselves or on a thin metallic ring which is adjustably mounted on thesupport for the diodes and the systems of lenses”. The disclosedinvention is “especially for scanning the circumferentially completeannular external surfaces of a series of coaxial cigarettes”.

Although the prior art disclosures of Smith et al., McLoughlin et al.,Bolt et al., and Heitmann et al., teach about electro-opticallyinspecting a longitudinally moving rod of material, such prior artteachings are solely based on generating, detecting (collecting andmeasuring), and analyzing, light ‘reflected by’ the outer or exposedsurfaces of the moving rods of material, and are not obviouslyextendable and/or applicable for generating, detecting (collecting andmeasuring), and analyzing, light ‘transmitted through’ the outer orexposed surfaces of the moving rods of material. Accordingly, such priorart teachings are not obviously extendable and/or applicable forelectro-optically measuring and analyzing ‘internal’ properties andcharacteristics, such as density, structure, defects, and impurities,and variabilities thereof, of a specified volumetric segment or numberof volumetric segments of the material making up or forming alongitudinally moving rod of material, according to the intended scopeand applications of the present invention.

In addition to the above described fundamental difference, a significantlimitation existing in the prior art of electro-optically inspecting alongitudinally moving rod of material, regards the undesirable affectthat temperature changes may have on accuracy and precision of theresults obtained from the electro-optical inspection process. Whileelectro-optically inspecting a longitudinally moving rod of material,temperature changes typically occur in critical regions of operation ofthe electro-optical inspection apparatus. Such critical regions ofoperation are particularly in the immediate vicinity of theelectro-optically inspected section of the moving rod of material.Magnitudes of such temperature changes may be sufficiently large so asto significantly increase noise and error levels during the illuminationand detection processes, which may translate to meaningful decreases inaccuracy and precision of the results obtained from the electro-opticalinspection process.

The prior art disclosures of Smith et al., McLoughlin et al., Bolt etal., and Heitmann et al., include no explicit or suggestive teaching ofa procedure or of equipment for monitoring, and/or compensating for,temperature changes, in the critical region of operation of theelectro-optical inspection apparatus.

Another significant limitation existing in the prior art ofelectro-optically inspecting a longitudinally moving rod of material,regards the undesirable affect that radially directed vibrating of thelongitudinally moving rod of material, in general, and of theelectro-optically inspected section of the longitudinally moving rod ofmaterial, in particular, during the electro-optical inspection process,may have on accuracy and precision of the results obtained from theelectro-optical inspection process. While electro-optically inspecting alongitudinally moving rod of material, the longitudinally moving rod ofmaterial, in general, and the electro-optically inspected section of thelongitudinally moving rod of material, in particular, typicallyvibrates, particularly, in the radial direction. Magnitudes of suchradially directed vibrating may be sufficiently large so as tosignificantly increase noise and error levels during the illuminationand detection processes, which may translate to meaningful decreases inaccuracy and precision of the results obtained from the electro-opticalinspection process.

The prior art disclosures of Smith et al., McLoughlin et al., Bolt etal., and Heitmann et al., include no explicit or suggestive teaching ofa procedure or of equipment for preventing, eliminating, or reducing,radially directed vibrating of the longitudinally moving rod ofmaterial, in general, and of the electro-optically inspected section ofthe longitudinally moving rod of material, in particular, during theelectro-optical inspection process.

In general, procedures and equipment for monitoring temperature and/orcompensating operation of a process for temperature changes, as well asprocedures and/or equipment for preventing, eliminating, or reducing,radially directed vibrating of a longitudinally moving object duringoperation of a process, are known and widely applicable, including on acommercial or manufacturing scale, and are well taught about. A possiblereason for absence of such teachings specifically in the prior art ofelectro-optically inspecting a longitudinally moving rod of material,for example, as taught about in the disclosures of Smith et al.,McLoughlin et al., Bolt et al., and Heitmann et al., is that thedisclosed electro-optical inspection methods and apparatuses, solelybased on generating, detecting (collecting and measuring), andanalyzing, light reflected by the outer or exposed surfaces of thelongitudinally moving rods of material, are insufficiently sensitive tobe significantly affected by the above described types of localtemperature changes and/or radially directed vibrating. This, therefore,precludes a need for monitoring temperature and/or compensating for suchlocal temperature changes, or, for preventing, eliminating, or reducing,such radially directed vibrating, of the longitudinally moving rod ofmaterial during the electro-optical inspection process.

Moreover, due to physical and/or electromechanical limitations,especially regarding design, construction, and operation, of theillumination and detection units in the electro-optical inspectionapparatuses taught about in McLoughlin et al., Bolt et al., and Heitmannet al., involving a plurality of miniaturized electro-optical components(in particular, light generating, conducting, emitting, and receiving,types of devices, mechanisms, components, and elements, such as LEDs,lenses, phototransistors, photosensitive transducers, fiber opticconductors or guides, and photoelectric elements) tightly configured andoriented within limited spaces, inclusion of a temperature monitoringand/or compensation procedure and equipment, and/or inclusion of avibrating prevention, reduction, and/or compensation, procedure andequipment, operative during the electro-optical inspection process, isnot readily accomplishable.

Accordingly, each of the above cited prior art, and similar prior art,feature several significant and fundamental limitations, and associatedlimitations thereof, with regard to the intended scope and applicationsof the present invention for electro-optically inspecting anddetermining internal properties and characteristics of a longitudinallymoving rod of material.

To one of ordinary skill in the art, there is thus a need for, and itwould be highly advantageous to have a method and device forelectro-optically inspecting and determining internal properties andcharacteristics, such as density, structure, defects, and impurities,and variabilities thereof, of a longitudinally moving rod of material.Moreover, there is a need for such an invention wherein the rod ofmaterial is continuously or intermittently moving along its longitudinalaxis during the electro-optical inspection process of measuring andanalyzing the internal properties and characteristics of a specifiedvolumetric segment or number of volumetric segments of thelongitudinally moving rod of material.

There is also a need for such an invention which is directed tocommercial applications requiring real time, non-invasive, high speed,high sensitivity, low noise, high accuracy, high precision, temperaturecompensative, and low vibration, measuring and analyzing of internalproperties and characteristics of a longitudinally moving rod ofmaterial, as the rod of material is transported or conveyed during acommercial manufacturing sequence, particularly a manufacturing sequenceincluding quality control and/or quality assurance processes. There isalso a need for such an invention which is generally applicable forinspecting and determining internal properties and characteristics of avariety of different types of a rod of material, for example, but notlimited to, a cigarette rod.

SUMMARY OF THE INVENTION

The present invention relates to a method and device forelectro-optically inspecting and determining internal properties andcharacteristics, such as density, structure, defects, and impurities,and variabilities thereof, of a longitudinally moving rod of material.The rod of material is continuously or intermittently moving along itslongitudinal axis while at least one focused beam of electromagneticradiation is incident upon, measurably affected by, and transmittedthrough, volumetric segments of the longitudinally moving rod ofmaterial, along with detecting the transmitted electromagnetic radiationbeam, during the electro-optical inspection process of measuring andanalyzing the internal properties and characteristics of thelongitudinally moving rod of material.

The present invention is generally applicable for inspecting anddetermining internal properties and characteristics of a variety ofdifferent types of a rod of material, as long as the rod of materialexhibits the behavior that an incident focused beam of electromagneticradiation, while not altering the rod of material, is affected by andtransmittable through volumetric segments of the rod of material. Forexample, but not limited to, a cigarette rod consisting of processedtobacco inside a rolled and sealed tube of cigarette wrapping paper.

The present invention is directed to commercial applications requiringreal time, non-invasive, high speed, high sensitivity, low noise, highaccuracy, high precision, temperature compensative, and low vibration,measuring and analyzing of internal properties and characteristics of alongitudinally moving rod of material, as the rod of material istransported or conveyed during a commercial manufacturing sequence,particularly a manufacturing sequence including quality control and/orquality assurance processes.

Thus, according to the present invention, there is provided a method forelectro-optically inspecting and determining internal properties andcharacteristics of a longitudinally moving rod of material, includingthe steps of: (a) guiding the longitudinally moving rod of materialalong its longitudinal axis by a rod guiding unit, along an optical pathwithin a transparent passageway, the optical path and the transparentpassageway coaxially extend along the longitudinal axis of the movingrod of material and pass through an electro-optical transmission module;(b) generating a focused beam of electromagnetic radiation by anillumination unit of the electro-optical transmission module, such thatthe focused beam is transmitted through a first side of the transparentpassageway and incident upon the rod of material longitudinally movingwithin the transparent passageway; (c) illuminating a volumetric segmentof the longitudinally moving rod of material by the incident focusedbeam, such that at least part of the incident focused beam is affectedby and transmitted through the volumetric segment and then transmittedthrough a second side of the transparent passageway, for forming a rodmaterial volumetric segment transmitted beam; and (d) detecting the rodmaterial volumetric segment transmitted beam by a detection unit of theelectro-optical transmission module, for forming a detected rod materialvolumetric segment transmitted beam useable for determining the internalproperties and characteristics of the longitudinally moving rod ofmaterial.

According to further features in preferred embodiments of the method ofthe invention described below, in step (b), generating the focused beamof electromagnetic radiation by the illumination unit further includes aprocedure for monitoring temperature and compensating for temperaturechanges in a critical region of operation of the illumination unit.

According to further features in preferred embodiments of the method ofthe invention described below, a critical region of operation is inimmediate vicinity of the volumetric segment of the rod of materiallongitudinally moving along the optical path within the transparentpassageway.

According to further features in preferred embodiments of the method ofthe invention described below, in step (b), operation of theillumination unit including the procedure for monitoring temperature andcompensating for temperature changes is based on a temperature changemonitoring and compensating electro-optical feedback loop.

According to further features in preferred embodiments of the method ofthe invention described below, in step (d), detecting the rod materialvolumetric segment transmitted beam by the detection unit furtherincludes a procedure for monitoring temperature and compensating fortemperature changes in a critical region of operation of the detectionunit.

According to further features in preferred embodiments of the method ofthe invention described below, a critical region of operation is inimmediate vicinity of the volumetric segment of the rod of materiallongitudinally moving along the optical path within the transparentpassageway.

According to further features in preferred embodiments of the method ofthe invention described below, in step (a), the optical path and thetransparent passageway coaxially extend along the longitudinal axis ofthe moving rod of material and pass through a plurality of twoelectro-optical transmission modules, such that longitudinal and angularor circumferential positions of the two electro-optical transmissionmodules, relative to each other, and relative to the transparentpassageway within which extends the coaxial optical path, are spatiallystaggered or displaced along the coaxial optical path, along which thelongitudinally moving rod of material is guided by the rod guiding unit.

According to further features in preferred embodiments of the method ofthe invention described below, the method further comprises a procedurefor preventing, eliminating, or reducing, radially directed vibrating ofthe longitudinally moving rod of material during electro-opticallyinspecting the longitudinally moving rod of material.

According to further features in preferred embodiments of the method ofthe invention described below, wherein following step (a) and precedingstep (b), there is inserted the step of generating a continuous vorticaltype of flow of gas within and along the transparent passageway by avortex generating mechanism, such that the flowing gas rotates as avortex around the optical path and around the longitudinally moving rodof material, and flows downstream within and along the transparentpassageway in same longitudinal direction of the longitudinally movingrod of material, such that the flowing gas radially impinges upon thelongitudinally moving rod of material within the transparent passageway;the flowing gas radially impinging upon the longitudinally moving rod ofmaterial prevents, eliminates, or reduces, radially directed vibratingof the longitudinally moving rod of material during theelectro-optically inspecting the longitudinally moving rod of material.

According to another aspect of the present invention, there is provideda method for preventing, eliminating, or reducing, radially directedvibrating of a longitudinally moving rod of material duringelectro-optically inspecting the longitudinally moving rod of material,comprising the steps of: (a) guiding the longitudinally moving rod ofmaterial along its longitudinal axis by a rod guiding unit, along anoptical path within a transparent passageway, the optical path and thetransparent passageway coaxially extend along the longitudinal axis ofthe longitudinally moving rod of material and pass through anelectro-optical inspection apparatus used for electro-opticallyinspecting the longitudinally moving rod of material; and (b) generatinga continuous vortical type of flow of gas within and along thetransparent passageway by a vortex generating mechanism, such that theflowing gas rotates as a vortex around the optical path and around thelongitudinally moving rod of material, and flows downstream within andalong the transparent passageway in same longitudinal direction of thelongitudinally moving rod of material, such that the flowing gasradially impinges upon the longitudinally moving rod of material withinthe transparent passageway; the flowing gas radially impinging upon thelongitudinally moving rod of material prevents, eliminates, or reduces,radially directed vibrating of the longitudinally moving rod of materialduring the electro-optically inspecting the longitudinally moving rod ofmaterial.

According to another aspect of the present invention, there is provideda device for electro-optically inspecting and determining internalproperties and characteristics of a longitudinally moving rod ofmaterial, comprising: (a) a rod guiding unit for guiding thelongitudinally moving rod of material along its longitudinal axis, alongan optical path within a transparent passageway, the optical path andthe transparent passageway coaxially extend along the longitudinal axisof the moving rod of material; and (b) an electro-optical transmissionmodule through which pass the optical path and the transparentpassageway, the electro-optical transmission module includes: (i) anillumination unit for generating a focused beam of electromagneticradiation, such that the focused beam is transmitted through a firstside of the transparent passageway and incident upon the rod of materiallongitudinally moving within the transparent passageway, the incidentfocused beam illuminates a volumetric segment of the longitudinallymoving rod of material, such that at least part of the incident focusedbeam is transmitted through the volumetric segment and through a secondside of the transparent passageway, for forming a rod materialvolumetric segment transmitted beam; and (ii) a detection unit fordetecting the rod material volumetric segment transmitted beam, forforming a detected rod material volumetric segment transmitted beamuseable for determining the internal properties and characteristics ofthe longitudinally moving rod of material.

According to further features in preferred embodiments of the device ofthe invention described below, the illumination unit for the generatingthe focused beam of electromagnetic radiation further includescomponents for monitoring temperature and compensating for temperaturechanges in a critical region of operation of the illumination unit.

According to further features in preferred embodiments of the device ofthe invention described below, wherein a critical region of operation isin immediate vicinity of the volumetric segment of the rod of materiallongitudinally moving along the optical path within the transparentpassageway.

According to further features in preferred embodiments of the device ofthe invention described below, operation of the illumination unitincluding the components for monitoring temperature and compensating fortemperature changes is based on a temperature change monitoring andcompensating electro-optical feedback loop.

According to further features in preferred embodiments of the method ofthe invention described below, the detection unit for detecting the rodmaterial volumetric segment transmitted beam further includes aprocedure for monitoring temperature and compensating for temperaturechanges in a critical region of operation of the detection unit.

According to further features in preferred embodiments of the device ofthe invention described below, a critical region of operation is inimmediate vicinity of the volumetric segment of the rod of materiallongitudinally moving along the optical path within the transparentpassageway.

According to further features in preferred embodiments of the device ofthe invention described below, the optical path and the transparentpassageway pass through a plurality of two electro-optical transmissionmodules, each the electro-optical transmission module includes aillumination unit and a detection unit.

According to further features in preferred embodiments of the device ofthe invention described below, the optical path and the transparentpassageway pass through a plurality of two electro-optical transmissionmodules, such that longitudinal and angular or circumferential positionsof the two electro-optical transmission modules, relative to each other,and relative to the transparent passageway within which extends thecoaxial optical path, are spatially staggered or displaced along thecoaxial optical path, along which the longitudinally moving rod ofmaterial is guided by the rod guiding unit.

According to further features in preferred embodiments of the device ofthe invention described below, wherein the rod guiding unit furtherincludes a vortex generating mechanism for generating a continuousvortical type of flow of gas within and along the transparentpassageway, such that the flowing gas rotates as a vortex around theoptical path and around the longitudinally moving rod of material, andflows downstream within and along the transparent passageway in samelongitudinal direction of the longitudinally moving rod of material,such that the flowing gas radially impinges upon the longitudinallymoving rod of material within the transparent passageway; the flowinggas impinging upon the longitudinally moving rod of material prevents,eliminates, or reduces, radially directed vibrating of thelongitudinally moving rod of material, during the electro-opticallyinspecting the longitudinally moving rod of material.

According to another aspect of the present invention, there is provideda device for preventing, eliminating, or reducing, radially directedvibrating of a longitudinally moving rod of material duringelectro-optically inspecting the longitudinally moving rod of material,comprising: a rod guiding unit for guiding the longitudinally moving rodof material along its longitudinal axis, along an optical path within atransparent passageway, the optical path and the transparent passagewaycoaxially extend along the longitudinal axis of the longitudinallymoving rod of material and pass through an electro-optical inspectionapparatus used for electro-optically inspecting the longitudinallymoving rod of material, the rod guiding unit includes a vortexgenerating mechanism for generating a continuous vortical type of flowof gas within and along the transparent passageway, such that theflowing gas rotates as a vortex around the optical path and around thelongitudinally moving rod of material, and flows downstream within andalong the transparent passageway in same longitudinal direction of thelongitudinally moving rod of material, such that the flowing gasradially impinges upon the longitudinally moving rod of material withinthe transparent passageway; the flowing gas impinging upon thelongitudinally moving rod of material prevents, eliminates, or reduces,radially directed vibrating of the longitudinally moving rod ofmaterial, during the electro-optically inspecting the longitudinallymoving rod of material.

Implementation of the method and device for electro-optically inspectingand determining internal properties and characteristics, such asdensity, structure, defects, and impurities, and variabilities thereof,of a longitudinally moving rod of material, of the present invention,involves performing steps and sub-steps in a manner selected from thegroup consisting of manually, semi-automatically, fully automatically,and a combination thereof, and involves operation of components,mechanisms, and elements, in a manner selected from the group consistingof manual, semi-automatic, fully automatic, and a combination thereof.Moreover, according to actual steps and sub-steps, components,mechanisms, and elements, used for implementing a particular embodimentof the disclosed invention, steps and sub-steps are performed by usinghardware, software, or an integrated combination thereof, and,components, mechanisms, and elements, operate by using hardware,software, or an integrated combination thereof.

In particular, software used for implementing the present inventionfeatures operatively connected and functioning written or printed data,in the form of software programs, software routines, softwaresub-routines, software symbolic languages, software code, softwareinstructions or protocols, or a combination thereof. Hardware used forimplementing the present invention features operatively connected andfunctioning electronic components and elements, in the form of acomputer chip, an integrated circuit, an electronic circuit, anelectronic sub-circuit, a hard-wired electrical circuit, or acombination thereof, involving digital and/or analog operations.Accordingly, an integrated combination of (1) software and (2) hardware,used for implementing the present invention, features an integratedcombination of (1) operatively connected and functioning written orprinted data, in the form of software programs, software routines,software sub-routines, software symbolic languages, software code,software instructions or protocols, or a combination thereof, and (2)operatively connected and functioning electronic components andelements, in the form of a computer chip, an integrated circuit, anelectronic circuit, an electronic sub-circuit, a hard-wired electricalcircuit, or a combination thereof, involving digital and/or analogoperations.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is herein described, by way of example only, withreference to the accompanying drawings. With specific reference now tothe drawings in detail, it is stressed that the particulars shown are byway of example and for purposes of illustrative description of thepreferred embodiments of the present invention only, and are presentedin the cause of providing what is believed to be the most useful andreadily understood description of the principles and conceptual aspectsof the present invention. In this regard, no attempt is made to showstructural details of the present invention in more detail than isnecessary for a fundamental understanding of the invention, thedescription taken with the drawings making apparent to those skilled inthe art how the several forms of the invention may be embodied inpractice. In the drawings:

FIG. 1 is a schematic diagram illustrating a partially perspectivecut-away sectional view of the first exemplary specific preferredembodiment of the generalized device for electro-optically inspectingand determining internal properties and characteristics of alongitudinally moving rod of material, in accordance with the presentinvention; and

FIG. 2 is a schematic diagram illustrating a partially perspectivecut-away sectional view of the second exemplary specific preferredembodiment of the generalized device for electro-optically inspectingand determining internal properties and characteristics of alongitudinally moving rod of material, in accordance with the presentinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to a method and device forelectro-optically inspecting and determining internal properties andcharacteristics, such as density, structure, defects, and impurities,and variabilities thereof, of a longitudinally moving rod of material.The rod of material is continuously or intermittently moving along itslongitudinal axis while a focused beam of electromagnetic radiation isincident upon, measurably affected by, and transmitted through,volumetric segments of the longitudinally moving rod of material, alongwith detecting the transmitted electromagnetic radiation beam, duringthe electro-optical inspection process of measuring and analyzing theinternal properties and characteristics of the longitudinally moving rodof material.

Steps, sub-steps, components, elements, operation, and implementation ofa method and device for electro-optically inspecting and determininginternal properties and characteristics, such as density, structure,defects, and impurities, and variabilities thereof, of a longitudinallymoving rod of material, according to the present invention, are betterunderstood with reference to the following description and accompanyingdrawings. Throughout the following description and accompanyingdrawings, same reference numbers refer to same components or sameelements.

In the following description of the method and device of the presentinvention, included are main or principal steps and sub-steps, and mainor principal devices, mechanisms, components, and elements, needed forsufficiently understanding proper ‘enabling’ utilization andimplementation of the disclosed method and device. Accordingly,description of various possible required and/or optional preliminary,intermediate, minor, steps, sub-steps, devices, mechanisms, components,and/or elements, which are readily known by one of ordinary skill in theart, and/or which are available in the prior art and technicalliterature relating to electro-optically inspecting a longitudinallymoving rod of material, and relating to principles and practice ofelectro-optics, are at most only briefly indicated herein.

It is to be understood that the present invention is not limited in itsapplication to the details of the order or sequence, and number, ofsteps and sub-steps of operation or implementation of the method, or tothe details of type, composition, construction, arrangement, order, andnumber, of the components and elements of the device, set forth in thefollowing description, accompanying drawings, or examples. For example,the following description refers to a reference XYZ coordinate system50, in order to illustrate implementation of the present invention.Other appropriate three-dimensional curvilinear coordinate systems, suchas a cylindrical coordinate system, is also useable as reference forillustrating the present invention. The present invention is capable ofother embodiments or of being practiced or carried out in various ways.Although steps, components, and materials, similar or equivalent tothose described herein can be used for practicing or testing the presentinvention, suitable steps, components, and materials, are describedherein.

It is also to be understood that unless otherwise defined, all technicaland scientific words, terms, and/or phrases, used herein have either theidentical or similar meaning as commonly understood by one of ordinaryskill in the art to which this invention belongs. Phraseology,terminology, and, notation, employed herein are for the purpose ofdescription and should not be regarded as limiting. Additionally, asused herein, the term ‘about’ refers to ±10% of the associated value.

Herein, internal properties and characteristics, such as density,structure, defects, and impurities, and variabilities thereof, of alongitudinally moving rod of material refer to the global, bulk, ormacroscopic, internal properties and characteristics, such as density,structure, defects, and impurities, and variabilities thereof, of aspecified volumetric segment or number of volumetric segments of thematerial, including bulk or macroscopic volume occupied by air andmoisture throughout the material, making up or forming thelongitudinally moving rod of material. These internal properties andcharacteristics of the longitudinally moving rod are to be clearlydistinguished from the local, molecular, or microscopic, properties andcharacteristics, such as molecular density, molecular structure,microscopic defects, and microscopic impurities, and variabilitiesthereof, of only the material, excluding bulk or macroscopic volumeoccupied by air and moisture, making up or forming the longitudinallymoving rod of material.

For example, internal properties and characteristics, such as density,structure, defects, and impurities, and variabilities thereof, of alongitudinally moving cigarette rod consisting of processed tobaccoinside a rolled and sealed tube of cigarette wrapping paper, refer tothe global, bulk, or macroscopic, density, structure, defects, andimpurities, and variabilities thereof, of a specified volumetric segmentor number of volumetric segments of the processed tobacco, includingbulk or macroscopic volume occupied by air and moisture throughout theprocessed tobacco, inside the rolled and sealed tube of cigarettewrapping paper. These internal properties and characteristics of thelongitudinally moving cigarette rod are to be clearly distinguished fromthe molecular density, molecular structure, microscopic defects, andmicroscopic impurities, and variabilities thereof, of only the processedtobacco molecules, excluding bulk or macroscopic volume occupied by airand moisture, making up or forming the longitudinally moving cigaretterod.

Herein, the phrase ‘electro-optical transmission module’ refers to aself-contained electro-optical device or assembly having a plurality ofoperatively connected electrical, electronic, optical, andelectro-optical or opto-electrical, components, elements, andappropriate circuitry, connections, and linkages, thereof, which isdesigned, structured, and functional, as a module. As disclosed herein,the electro-optical transmission module performs electro-opticalfunctions, involving digital and/or analog operations, described in theform of steps and sub-steps, for generating a focused beam ofelectromagnetic radiation which becomes incident upon a longitudinallymoving rod of material, for illuminating volumetric segments of thelongitudinally moving rod of material by the incident focused beam, suchthat at least part of the incident focused beam is affected by andtransmitted through volumetric segments of the longitudinally moving rodof material, and for detecting the transmitted electromagnetic radiationbeam, during the electro-optical inspection process of measuring andanalyzing internal properties and characteristics of the longitudinallymoving rod of material.

In other words, the electro-optical transmission module as hereinillustratively described, is specifically designed, structured, andfunctional, for electro-optically transmitting electromagnetic radiationbeams through a longitudinally moving rod of material, and forelectro-optically detecting the affected transmitted electromagneticradiation beams thereof. Moreover, the electro-optical transmissionmodule of the present invention is designed, structured, and functional,for being connectable to, and operable with, one or more other elements,components, mechanisms, devices, units, and/or systems.

The electro-optical transmission module of the present invention is tobe clearly distinguished from an electro-optical device or assembly,which may be in a modular form, which is specifically designed,structured, and functional, for electro-optically generating a focusedbeam of electromagnetic radiation which becomes incident upon a movingrod of material, such as a longitudinally moving rod of material, forilluminating the outer or exposed surface (and not internal volumetricsegments) of the longitudinally moving rod of material by the incidentfocused beam, such that at least part of the incident focused beam isaffected and reflected by (and not transmitted through), the outer orexposed surface of the longitudinally moving rod of material, and fordetecting the reflected electromagnetic radiation beam, during anelectro-optical inspection process of measuring and analyzing external(and not internal) properties and characteristics of the longitudinallymoving rod of material.

Immediately following, there is first a listing of the main steps of thegeneralized method, and of the main components of the correspondinggeneralized device for implementing thereof, of the present invention.Thereafter, are highlighted main aspects of novelty and inventiveness,and, beneficial and advantageous features and characteristics, of thepresent invention. Thereafter, are illustratively described the stepsand sub-steps of the generalized method, and the components, elements,operation, and implementation, of the generalized device, of the presentinvention, with reference to two exemplary specific preferredembodiments of the generalized device of the present invention.

The generalized method for electro-optically inspecting and determininginternal properties and characteristics of a longitudinally moving rodof material, herein, also referred to as the generalized electro-opticalinspection method, of the present invention, includes the main steps of:(a) guiding the longitudinally moving rod of material along itslongitudinal axis by a rod guiding unit, along an optical path within atransparent passageway, the optical path and the transparent passagewaycoaxially extend along the longitudinal axis of the moving rod ofmaterial and pass through an electro-optical transmission module; (b)generating a focused beam of electromagnetic radiation by anillumination unit of the electro-optical transmission module, such thatthe focused beam is transmitted through a first side of the transparentpassageway and incident upon the rod of material longitudinally movingwithin the transparent passageway; (c) illuminating a volumetric segmentof the longitudinally moving rod of material by the incident focusedbeam, such that at least part of the incident focused beam is affectedby and transmitted through the volumetric segment and then transmittedthrough a second side of the transparent passageway, for forming a rodmaterial volumetric segment transmitted beam; and (d) detecting the rodmaterial volumetric segment transmitted beam by a detection unit of theelectro-optical transmission module, for forming a detected rod materialvolumetric segment transmitted beam useable for determining the internalproperties and characteristics of the longitudinally moving rod ofmaterial.

For achieving higher sensitivity, signal to noise ratios, accuracy, andprecision, and therefore, overall performance, of step (b)—generatingthe incident focused beam of electromagnetic radiation by theillumination unit, and/or of step (d)—detecting the rod materialvolumetric segment transmitted beam by the detection unit, in thegeneralized electro-optical inspection method, preferably, in a specificpreferred embodiment of the generalized electro-optical inspectionmethod, step (b) and/or step (d) further includes sub-steps andprocedures, implemented via corresponding algorithms and softwareprograms, and components for performing thereof, in particular, at leastone strategically located temperature sensor, such as a thermocouple,and associated electro-optical circuitry, for monitoring temperature andcompensating for temperature changes in critical regions of operation ofthe illumination unit and the detection unit of the electro-opticaltransmission module of the electro-optical inspection device. Suchcritical regions of operation are particularly in the immediate vicinityof the electro-optically inspected volumetric segment of the rod ofmaterial longitudinally moving along the optical path within thetransparent passageway, during the electro-optical inspection process.

For achieving even higher sensitivity, signal to noise ratios, accuracy,and precision, and therefore, overall performance, of steps (a) through(d) in the generalized electro-optical inspection method, preferably, aspecific preferred embodiment of the generalized electro-opticalinspection method further includes sub-steps and procedures, andcomponents for performing thereof, for preventing, eliminating, or atleast reducing, radially directed vibrating of the longitudinally movingrod of material, in general, and of the electro-optically inspectedvolumetric segment of the longitudinally moving rod of material, inparticular, during the electro-optical inspection process. Inparticular, preferably, following step (a) and preceding step (b) in thegeneralized electro-optical inspection method of the present invention,there is inserted the step of generating a continuous vortical type offlow of gas within and along the transparent passageway by a vortexgenerating mechanism, preferably, included as a component of the rodguiding unit, such that the flowing gas rotates as a vortex around theoptical path and around the moving rod of material, and flows downstreamwithin and along the transparent passageway in the same longitudinaldirection of the moving rod of material, such that the flowing gasradially impinges upon the longitudinally moving rod of material withinthe transparent passageway. The flowing gas radially impinging upon thelongitudinally moving rod of material prevents, eliminates, or reduces,radially directed vibrating of the longitudinally moving rod of materialduring the steps (a) through (d), during the electro-opticallyinspecting and determining the internal properties and characteristicsof the longitudinally moving rod of material.

A specific preferred embodiment of the generalized electro-opticalinspection method, of the present invention, further includes step (e):processing and analyzing the focused beam of step (b), the incidentfocused beam of step (c), and the rod material detected volumetricsegment transmitted beam of step (d), by a process control and dataanalysis unit, for determining the internal properties andcharacteristics, such as density, structure, defects, and impurities,and variabilities thereof, of the longitudinally moving rod of material.Optionally, a specific preferred embodiment of the generalizedelectro-optical inspection method further includes step (f): controllinglongitudinal movement of the longitudinally moving rod of material, bythe process control and data analysis unit operatively connected to arod moving unit, where the rod moving unit is operatively connected tothe rod guiding unit, and the rod moving unit longitudinally moves therod of material along its longitudinal axis.

The corresponding generalized device for electro-optically inspectingand determining internal properties and characteristics of alongitudinally moving rod of material, herein, also referred to as thegeneralized electro-optical inspection device, of the present invention,includes the main components: (a) a rod guiding unit for guiding thelongitudinally moving rod of material along its longitudinal axis, alongan optical path within a transparent passageway, the optical path andthe transparent passageway coaxially extend along the longitudinal axisof the moving rod of material; and (b) an electro-optical transmissionmodule through which pass the optical path and the transparentpassageway, the electro-optical transmission module includes: (i) anillumination unit for generating a focused beam of electromagneticradiation, such that the focused beam is transmitted through a firstside of the transparent passageway and incident upon the rod of materiallongitudinally moving within the transparent passageway, the incidentfocused beam illuminates a volumetric segment of the longitudinallymoving rod of material, such that at least part of the incident focusedbeam is affected by and transmitted through the volumetric segment andthen transmitted through a second side of the transparent passageway,for forming a rod material volumetric segment transmitted beam; and (ii)a detection unit for detecting the rod material volumetric segmenttransmitted beam, for forming a detected rod material volumetric segmenttransmitted beam useable for determining the internal properties andcharacteristics of the longitudinally moving rod of material.

For achieving high speed, sensitivity, signal to noise ratios, accuracy,and precision, and therefore, overall performance, of the illuminationunit for generating the focused beam and the incident focused beam ofelectromagnetic radiation, and of the detection unit for detecting therod material volumetric segment transmitted beam, in the generalizedelectro-optical inspection device, preferably, in a specific preferredembodiment of the generalized electro-optical inspection device, each ofthe illumination unit, the detection unit, and preferably, a housing ofselected components of these units, includes components, in particular,at least one strategically located temperature sensor, such as athermocouple, and associated electro-optical circuitry, and, sub-stepsand procedures, implemented via corresponding algorithms and softwareprograms, for operating thereof, for monitoring temperature andcompensating for temperature changes in critical regions of operation ofthe illumination unit and the detection unit of the electro-opticaltransmission module of the electro-optical inspection device. Suchcritical regions of operation are particularly in the immediate vicinityof the electro-optically inspected volumetric segment of the rod ofmaterial longitudinally moving along the optical path within thetransparent passageway, during the electro-optical inspection process.

For achieving even higher sensitivity, signal to noise ratios, accuracy,and precision, and therefore, overall performance, of operation of therod guiding unit and of the electro-optical transmission module in thegeneralized electro-optical inspection device, preferably, in a specificpreferred embodiment of the generalized electro-optical inspectiondevice, the rod guiding unit further includes components, and, sub-stepsand procedures for operating thereof, for preventing, eliminating, or atleast reducing, radially directed vibrating of the longitudinally movingrod of material, in general, and of the electro-optically inspectedvolumetric segment of the longitudinally moving rod of material, inparticular, during the electro-optical inspection process.

In particular, preferably, the rod guiding unit in the generalizeddevice of the present invention further includes a vortex generatingmechanism, for generating a continuous vortical type of flow of gaswithin and along the transparent passageway, such that the flowing gasrotates as a vortex around the optical path and around the moving rod ofmaterial, and flows downstream within and along the transparentpassageway in the same longitudinal direction of the moving rod ofmaterial, such that the flowing gas radially impinges upon thelongitudinally moving rod of material within the transparent passageway.The flowing gas radially impinging upon the longitudinally moving rod ofmaterial prevents, eliminates, or reduces, radially directed vibratingof the longitudinally moving rod of material during operation of the rodguiding unit and during operation of the electro-optical transmissionmodule, during the electro-optically inspecting and determining of theinternal properties and characteristics of the longitudinally moving rodof material.

A specific preferred embodiment of the generalized electro-opticalinspection device, of the present invention, further includes component(c): a process control and data analysis unit, which functions for (1)controlling the illumination unit, and selected components thereof, andthe detection unit, and selected components thereof, of theelectro-optical transmission module, and for (2) processing andanalyzing the focused beam and the incident focused beam generated bythe illumination unit, and the rod material detected volumetric segmenttransmitted beam detected by the detection unit, for determining theinternal properties and characteristics, such as density, structure,defects, and impurities, and variabilities thereof, of thelongitudinally moving rod of material. Optionally, in a specificpreferred embodiment of the generalized electro-optical inspectiondevice, the process control and data analysis unit also functions for(3) controlling a rod moving unit, operatively connected to the rodguiding unit, where the rod moving unit longitudinally moves the rod ofmaterial along its longitudinal axis.

A main aspect of novelty and inventiveness of the present invention isthat it is based on using electro-optics for inspecting and determininginternal properties and characteristics, such as density, structure,defects, and impurities, and variabilities thereof, of a longitudinallymoving rod of material, and is fully applicable for inclusion in acommercial production or manufacturing sequence. This is accomplished byimplementing the herein disclosed electro-optical inspection method anddevice, wherein the rod of material is continuously or intermittentlymoving along its longitudinal axis while at least one focused beam ofelectromagnetic radiation is incident upon, measurably affected by, andtransmitted through, volumetric segments of the longitudinally movingrod of material, along with detecting the transmitted electromagneticradiation beam, during the electro-optical inspection process ofmeasuring and analyzing the internal properties and characteristics ofthe longitudinally moving rod of material.

This is in strong contrast to prior art teachings of methods, devices,and systems, for electro-optically inspecting and determining ‘external’(and not ‘internal’) properties and characteristics, such as uniformity,structure, color, print, closures, openings, defects (for example,holes, defective and/or missing components), and impurities, andvariabilities thereof, of or on the ‘outer or exposed surface’ (and notof or in a specified ‘volumetric segment’ or number of ‘volumetricsegments’) of a continuously or intermittently moving rod of material,where the rod of material is continuously or intermittently movingsideways along or rolling around its ‘radial’ axis (and not moving alongits ‘longitudinal’ axis), or is continuously or intermittently movingalong its longitudinal axis, during the actual electro-opticalinspection process. Such prior art is based on generating, detecting(collecting and measuring), and analyzing, light ‘reflected by’ (and nottransmitted through) the outer or exposed surface of the continuously orintermittently moving rod of material.

Another main aspect of novelty and inventiveness of the presentinvention is that the disclosed electro-optical inspection method anddevice each includes sub-steps and procedures, implemented viacorresponding algorithms and software programs, and components forperforming thereof, in particular, at least one strategically locatedtemperature sensor, such as a thermocouple, and associatedelectro-optical circuitry, for monitoring temperature and compensatingfor temperature changes in critical regions of operation of theillumination unit and the detection unit of the electro-opticaltransmission module of the electro-optical inspection device. Suchcritical regions of operation are particularly in the immediate vicinityof the electro-optically inspected volumetric segment of the rod ofmaterial longitudinally moving along the optical path within thetransparent passageway, during the electro-optical inspection process.This enables achieving higher sensitivity, signal to noise ratios,accuracy, and precision, and therefore, overall performance, ofgenerating the incident focused beam of electromagnetic radiation by theillumination unit of the electro-optical transmission module, and ofdetecting the rod material volumetric segment transmitted beam by thedetection unit of the electro-optical transmission module.

Another main aspect of novelty and inventiveness of the presentinvention is that preferably, the disclosed electro-optical inspectionmethod and device each includes sub-steps and procedures, and componentsfor performing thereof, for preventing, eliminating, or at leastreducing, radially directed vibrating of the longitudinally moving rodof material, in general, and of the electro-optically inspectedvolumetric segment of the longitudinally moving rod of material, inparticular, during the electro-optical inspection process. Inparticular, preferably, the electro-optical inspection method and deviceeach includes generating a continuous vortical type of flow of gaswithin and along the transparent passageway by a vortex generatingmechanism, preferably, included as a component of the rod guiding unit,such that the flowing gas rotates as a vortex around the optical pathand around the moving rod of material, and flows downstream within andalong the transparent passageway in the same longitudinal direction ofthe moving rod of material, such that the flowing gas radially impingesupon the longitudinally moving rod of material within the transparentpassageway. The flowing gas radially impinging upon the longitudinallymoving rod of material prevents, eliminates, or reduces, radiallydirected vibrating of the longitudinally moving rod of material duringoperation of the rod guiding unit and during operation of theelectro-optical transmission module, during the electro-opticallyinspecting and determining of the internal properties andcharacteristics of the longitudinally moving rod of material.

The electro-optical inspection method and device of the presentinvention have several beneficial and advantageous features andcharacteristics, which are based on, in addition to, or a consequenceof, the above described main aspects of novelty and inventiveness.

First, the present invention is generally applicable for inspecting anddetermining internal properties and characteristics of a variety ofdifferent types of a rod of material, as long as the rod of materialexhibits the behavior that an incident focused beam of electromagneticradiation, while not altering the rod of material, is affected by andtransmittable through volumetric segments of the rod of material. Forexample, but not limited to, a cigarette rod consisting of processedtobacco inside a rolled and sealed tube of cigarette wrapping paper.

Second, the present invention is directed to commercial applicationsrequiring real time, non-invasive, high speed, high sensitivity, lownoise, high accuracy, high precision, temperature compensative, and lowvibration, measuring and analyzing of internal properties andcharacteristics of a continuously or intermittently longitudinallymoving rod of material, as the rod of material is transported orconveyed during a commercial manufacturing sequence, particularly amanufacturing sequence including quality control and/or qualityassurance processes. For example, in the case of manufacturingcigarettes, the present invention is directly applicable for inclusionas part of an overall commercial cigarette manufacturing sequence,during which bulk quantities of cut and processed tobacco leaves, alongwith any number of cigarette tobacco additives or ingredients, exitingan upstream manufacturing process are rolled, wrapped, and sealed,inside cigarette wrapping paper, and continuously or intermittentlylongitudinally transported or conveyed, for example, at a speed ofbetween about 5 to 20 meters per second, as long, narrow, continuoustobacco filled cylinders or rods prior to entering further downstreamprocesses, including for example, a cigarette rod cutting process, and arod segment rejecting process, eventually leading to production of bulkquantities of individually cut, wrapped, and non-filtered or filtered,cigarettes in a box, for example, at a rate of about 10,000 cigarettesper minute.

Third, the present invention features modularity, based on design,construction, and operation, of the electro-optical inspection device,and operation thereof, in general, with respect to the electro-opticaltransmission module, in particular, through which passes the opticalpath within the transparent passageway. More specifically, it isstraightforward to extend the present invention from an embodimenthaving a single electro-optical transmission module, operative with asingle synchronized paired or coupled illumination unit/detection unit,to a larger embodiment having a plurality of electro-opticaltransmission modules, each fully operative with its own synchronizedpaired or coupled illumination unit/detection unit, and housing thereof,through which passes the same transparent passageway within which is thesame coaxial optical path along which the longitudinally moving rod ofmaterial is guided by the rod guiding unit.

Fourth, in such a larger embodiment, each of the plurality ofelectro-optical transmission modules is positionable at a differentlongitudinal position or location around and along the same transparentpassageway within which extends the same coaxial optical path, and ispositionable at either the same or at a different angular, radial, orcircumferential, position or location around the transparent passageway.More specifically, this is accomplished by spatially staggering ordisplacing the longitudinally and angular, radial, or circumferential,positions or locations of the electro-optical transmission modulesrelative to each other, and relative to the same transparent passagewaywithin which extends the same coaxial optical path of the longitudinallymoving rod of material.

An embodiment having spatially staggered or displaced positions orlocations of a plurality of electro-optical transmission modulessignificantly decreases potential cross interferences among the variouselectromagnetic radiation beams emanating from, propagating through,transmitted into, out of, or through, and, entering into or exiting outof, the illumination units, the first and second side of the transparentpassageway, the volumetric segments of the moving rod of material, andthe detection units, of the plurality of electro-optical transmissionmodules. Additionally, spatially staggering or displacing the positionsor locations of two or more electro-optical transmission modules enableseach volumetric segment of the longitudinally moving rod of material tobe inspected for a sufficiently integratable amount of time by thesynchronized paired or coupled illumination unit/detection unit of eachelectro-optical transmission module. These factors contribute toachieving higher speed, sensitivity, signal to noise ratios, accuracy,and precision, and therefore, overall performance, of such a largerembodiment of the electro-optical inspection method and device, comparedto an embodiment of the electro-optical inspection method and devicehaving a single electro-optical transmission module.

Fifth, the present invention is highly flexible, in that theelectro-optical transmission module, in general, and, the paired orcoupled illumination unit/detection unit thereof, in particular, aretotally functional by using different types of electrical, electronic,optical, and electro-optical or opto-electrical, components, elements,and appropriate circuitry, connections, and linkages, thereof, forexample, based on either light emitting diode (LED) technology or fiberoptic technology, which are designed, structured, and functional, as amodule, and perform the herein described electro-optical functions,involving digital and/or analog operations.

Sixth, the present invention is highly flexible, in that it is operableaccording to different temporal modes, involving continuous ordiscontinuous operation of the electro-optical transmission module, ingeneral, and, of the paired or coupled illumination unit/detection unitthereof, in particular, during the electro-optical inspection of thelongitudinally moving rod of material.

More specifically, while the longitudinally moving rod of material iscontinuously or intermittently moving and being guided through a singleelectro-optical transmission module, or through a plurality ofelectro-optical transmission modules, the corresponding illuminationunits and detection units are continuously or discontinuously activatedaccording to a pre-determined timing or switching schedule or sequence,in particular, via applying an appropriate synchronous or asynchronouson/off switching schedule or sequence for operating the illuminationunits and detection units. Additionally and/or alternatively, theelectro-optical inspection device is connectable to and operable with aprocess control and data analysis unit, which is capable of controllingany of the steps and sub-steps, and components for performing thereof,and is capable of analyzing the rod material volumetric segment baseddata and information obtained therefrom, according to a spatiallystaggered configuration, a temporally continuous or discontinuous mode,and/or a combination thereof, in real time during the electro-opticalinspection process of measuring and analyzing the internal propertiesand characteristics of the longitudinally moving rod of material.

Based upon the above described aspects of novelty and inventiveness,and, beneficial and advantageous features and characteristics, thepresent invention successfully addresses and overcomes limitations, andwidens the scope, of prior art teachings of electro-optically inspectinga longitudinally moving rod of material.

Following are illustratively described the steps and sub-steps of thegeneralized electro-optical inspection method, and the components,elements, operation, and implementation, of the generalizedelectro-optical inspection device, for electro-optically inspecting anddetermining internal properties and characteristics, such as density,structure, defects, and impurities, and variabilities thereof, of alongitudinally moving rod of material, of the present invention, withreference to two exemplary specific preferred embodiments of thegeneralized electro-optical inspection device, as illustrated in FIGS. 1and 2.

In the following illustrative description, same reference numbers referto same units, same components, or same elements. For particularlyunderstanding and viewing the second exemplary specific preferredembodiment of the generalized electro-optical inspection deviceillustrated in FIG. 2, relative to the first exemplary specificpreferred embodiment illustrated in FIG. 1, in FIG. 2, each unit,component, or element, which appears and is referenced as a unit,component, or element, that ‘is part’ of a plurality of the same units,components, or elements, is assigned a reference number with a lettersuffix, that is, with an ‘a’ or ‘b’, with the same correspondingnumerical reference number as used for describing that same unit,component, or element, which appears and is referenced in FIG. 1.Accordingly, in FIG. 2, each unit, component, or element, which appearsor is referenced as a unit, component, or element, that ‘is not part’ ofa plurality of the same units, components, or elements, respectively, isassigned a reference number ‘without’ a letter suffix, that is, withoutan ‘a’ or ‘b’, and corresponds to the same numerical reference number asused for describing that same unit, component, or element, which appearsand is referenced in FIG. 1.

Thus, it is to be clearly understood, that unless otherwise stated,description of the structure and function, and method of implementing oroperating, of each unit, component, and element, of the first exemplaryspecific preferred embodiment of the generalized electro-opticalinspection device illustrated in FIG. 1, as example, is fully andequally applicable to the correspondingly same unit, component, andelement, respectively, of the second exemplary specific preferredembodiment of the generalized electro-optical inspection deviceillustrated in FIG. 2. Repetition of description of the presentinvention occurs where considered appropriate for properly and fullyunderstanding the similarities and differences between the first andsecond exemplary specific preferred embodiments of the generalizedelectro-optical inspection device illustrated in FIGS. 1 and 2, andmethod of implementing or operating each embodiment thereof.

As illustrated in FIG. 1, a schematic diagram illustrating a partiallyperspective cut-away sectional view of the first exemplary specificpreferred embodiment of the generalized device, hereinafter, referred toas electro-optical inspection device 10, for electro-opticallyinspecting and determining internal properties and characteristics of alongitudinally moving rod of material, hereinafter, for brevity, alsoreferred to as moving rod of material 12, or more briefly, rod ofmaterial 12, electro-optical inspection device 10 includes a singleelectro-optical transmission module 24 through which passes thetransparent passageway 22, within which is the coaxial optical path 20along which the longitudinally moving rod of material 12 is guided bythe rod guiding unit 14.

As illustrated in FIG. 2, a schematic diagram illustrating a partiallyperspective cut-away sectional view of the second exemplary specificpreferred embodiment of the generalized device, hereinafter, referred toas electro-optical inspection device 60, for electro-opticallyinspecting and determining internal properties and characteristics of alongitudinally moving rod of material, electro-optical inspection device60 includes an exemplary plurality of two electro-optical transmissionmodules 24, that is 24 a and 24 b, through which passes the sametransparent passageway 22, within which is the same coaxial optical path20 along which the longitudinally moving rod of material 12 is guided bythe rod guiding unit 14.

As clearly shown in FIG. 2, with reference to reference XYZ coordinatesystem 50, in electro-optical inspection device 60, the longitudinal andangular, radial, or circumferential, positions or locations of the twoelectro-optical transmission modules 24 a and 24 b, in general, and theunits of each respective module, in particular, relative to each other,and relative to the same transparent passageway 22 within which extendscoaxial optical path 20, are spatially staggered or displaced along thesame coaxial optical path 20, along which the longitudinally moving rodof material 12 is guided by the rod guiding unit 14. This translates toachieving higher speed, sensitivity, signal to noise ratios, accuracy,and precision, and therefore, overall performance, of theelectro-optical inspection method implemented by using electro-opticalinspection device 60, having two electro-optical transmission modules 24a and 24 b, in the second exemplary specific preferred embodimentillustrated in FIG. 2, compared to using electro-optical inspectiondevice 10, having a single electro-optical transmission module 24, inthe first exemplary specific preferred embodiment illustrated in FIG. 1,of the generalized electro-optical inspection device forelectro-optically inspecting and determining internal properties andcharacteristics of the longitudinally moving rod of material 12.

Throughout the following illustrative description of the first andsecond exemplary specific preferred embodiments of the generalizeddevice for electro-optically inspecting and determining internalproperties and characteristics of a longitudinally moving rod ofmaterial, of the present invention, as illustrated in FIGS. 1 and 2,respectively, it is to be clearly understood that electro-opticalinspection device 10 (FIG. 1), including the single electro-opticaltransmission module 24 through which passes the transparent passageway22, and electro-optical inspection device 60 (FIG. 2), including the twoelectro-optical transmission modules 24 a and 24 b through which passesthe same transparent passageway 22, correspond to two different, butgenerically related, exemplary specific preferred embodiments ‘of thesame’ generalized electro-optical inspection device, implementedaccording ‘to the same’ generalized electro-optical inspection method,of the present invention, and do not correspond to two different,unrelated and/or independent devices.

As shown in each of FIGS. 1 and 2, moving rod of material 12 islongitudinally moved along its longitudinal axis by a rod moving unit 5.In FIGS. 1 and 2, with reference to reference XYZ coordinate system 50,it is to be viewed and understood that the longitudinal direction ofmovement of moving rod of material 12 is, for example, in theZ-direction and is coaxial with the longitudinal axis of moving rod ofmaterial 12, extending between rod material entrance area 16 and rodmaterial exit area 18 (indicated in FIGS. 1 and 2 by the straight andhollow open-tail reference arrows on the lower left side and on theupper right side, respectively) of rod guiding unit 14 in eachelectro-optical inspection device 10 and electro-optical inspectiondevice 60, respectively.

As shown in FIGS. 1 and 2, rod moving unit 5 provides and supplieslongitudinally moving rod of material 12 to each of electro-opticalinspection device 10 and electro-optical inspection device 60,respectively, via rod material entrance area 16. For example, in thecase of manufacturing cigarettes, each of electro-optical inspectiondevice 10 and electro-optical inspection device 60, of the presentinvention, is directly applicable for inclusion as part of an overallcommercial cigarette manufacturing sequence. In such an overallcommercial cigarette manufacturing sequence, bulk quantities of cut andprocessed tobacco leaves, along with any number of cigarette tobaccoadditives or ingredients, exiting an upstream manufacturing process arerolled, wrapped, and sealed, inside cigarette wrapping paper, andcontinuously or intermittently longitudinally transported or conveyed bya rod moving system, device, or mechanism, such as rod moving unit 5,for example, at a speed of between about 5 to 20 meters per second, aslong, narrow, continuous tobacco filled cylinders or rods prior toentering further downstream processes, including for example, acigarette rod cutting process, and a rod section or segment rejectingprocess, eventually leading to production of bulk quantities ofindividually cut, wrapped, and non-filtered or filtered, cigarettes in abox, for example, at a rate of about 10,000 cigarettes per minute.

Automatic operation of rod moving unit 5, including for example, controlof the linear speed at which rod moving unit 5 moves rod of material 12along its longitudinal axis to each electro-optical inspection device 10and 60, respectively, via rod material entrance area 16 is performed bya process control and data analysis unit, such as process control anddata analysis unit 120. Preferably, rod moving unit 5 either includes,or is operatively connected to, a rod moving unit mechanism 7, whichprovides a real time rod moving unit clock output signal 9, thatincludes data and information about the rate or linear speed at whichrod moving unit 5 moves rod of material 12.

In Step (a) of the generalized electro-optical inspection method forelectro-optically inspecting and determining internal properties andcharacteristics of a longitudinally moving rod of material, of thepresent invention, there is guiding the longitudinally moving rod ofmaterial along its longitudinal axis by a rod guiding unit, along anoptical path within a transparent passageway, the optical path and thetransparent passageway coaxially extend along the longitudinal axis ofthe moving rod of material and pass through an electro-opticaltransmission module.

In the first exemplary specific preferred embodiment of the generalizeddevice for electro-optically inspecting and determining internalproperties and characteristics of a longitudinally moving rod ofmaterial, that is, moving rod of material 12, as illustrated in FIG. 1,electro-optical inspection device 10 includes the main components: (a) arod guiding unit 14, and (b) an electro-optical transmission module 24.

In electro-optical inspection device 10, rod guiding unit 14 is forguiding moving rod of material 12 along its longitudinal axis, extendingbetween rod material entrance area 16 and rod material exit area 18 ofelectro-optical inspection device 10, along an optical path 20 (in FIG.1, indicated by the dotted line 20 drawn along the length of moving rodof material 12) within a transparent passageway 22, where optical path20 and transparent passageway 22 coaxially extend along the longitudinalaxis of moving rod of material 12. Preferably, rod guiding unit 14 isoperatively connected to a rod moving unit, such as rod moving unit 5,for receiving longitudinally moving rod of material 12 provided andsupplied by rod moving unit 5, for example, via rod material entrancearea 16.

Rod guiding unit 14 includes the main components: (i) a transparenthousing 62, and (ii) a rod material entrance assembly 64.

In rod guiding unit 14, transparent housing 62 is for housing, holding,or confining, transparent passageway 22 within which is coaxial opticalpath 20, along which is guided longitudinally moving rod of material 12.Transparent housing 62 is, preferably, of a hollow tubular orcylindrical geometrical shape, and constructed from an opticallytransparent material, for example, a plastic, a glass, a transparentcomposite material, or a combination thereof.

Rod material entrance assembly 64 is operatively attached or connectedto transparent housing 62, and functions as an entrance for thelongitudinally moving rod of material 12 entering into electro-opticalinspection device 10, via rod material entrance area 16. Preferably, rodmaterial entrance assembly 64 is operatively connected to a rod movingunit, such as rod moving unit 5, thereby enabling operative connectionof rod guiding unit 14 with rod moving unit 5. Rod material entranceassembly 64 is preferably of a mostly hollow tubular or cylindricalgeometrical shape, and constructed from a metallic material, anon-metallic material, a composite material, or a combination thereof,for enabling operative attachment or connection to transparent housing62 and for enabling guiding of the moving rod of material 12 along itslongitudinal axis along optical path 20 within coaxial transparentpassageway 22.

For proper implementation of the electro-optical inspection method andelectro-optical inspection device 10, the optically transparent materialof transparent housing 62 in rod guiding unit 14 is compatible with theproperties, characteristics, and operation, of illumination unit 26.Especially, regarding wavelength or frequency, and intensity or power,of electromagnetic radiation source beam 44 generated by illuminationunit 26, such that focused beam 28 is transmittable through first side30 of transparent passageway 22 and subsequently incident uponvolumetric segment 34 of rod of material 12 longitudinally moving withintransparent passageway 22.

Moreover, this compatibility is such that subsequent to incident focusedbeam 32 illuminating volumetric segment 34 of moving rod of material 12,and subsequent to at least part of incident focused beam 32 beingaffected by and transmitted through volumetric segment 34, the affectedincident focused beam exiting volumetric segment 34 is thentransmittable through second side 36 of transparent passageway 22, forforming rod material volumetric segment transmitted beam 38. This inturn, enables detection of rod material volumetric segment transmittedbeam 38, for forming detected rod material volumetric segmenttransmitted beam 38′ useable for determining the internal properties andcharacteristics of the longitudinally moving rod of material 12.

In Step (b), there is generating a focused beam of electromagneticradiation by an illumination unit of the electro-optical transmissionmodule, such that the focused beam is transmitted through a first sideof the transparent passageway and incident upon the rod of materiallongitudinally moving within the transparent passageway. In Step (c),there is illuminating a volumetric segment of the longitudinally movingrod of material by the incident focused beam, such that at least part ofthe incident focused beam is affected by and transmitted through thevolumetric segment and then transmitted through a second side of thetransparent passageway, for forming a rod material volumetric segmenttransmitted beam.

In electro-optical inspection device 10, as illustrated in FIG. 1,electro-optical transmission module 24 through which pass optical path20 and transparent passageway 22, includes the main components: (i) anillumination unit 26, and (ii) a detection unit 40.

Illumination unit 26 is for generating a focused beam 28 ofelectromagnetic radiation, such that focused beam 28 is transmittedthrough a first side 30 of transparent passageway 22 and incident uponrod of material 12 longitudinally moving within transparent passageway22, and the incident focused beam 32 illuminates a volumetric segment 34of longitudinally moving rod of material 12, such that at least part ofincident focused beam 32 is affected by and transmitted throughvolumetric segment 34 and then transmitted through a second side 36 oftransparent passageway 22, for forming a rod material volumetric segmenttransmitted beam 38.

In a first specific configuration of illumination unit 26 inelectro-optical transmission module 24 of electro-optical inspectiondevice 10, illumination unit 26 includes the main components: (1) anelectromagnetic radiation beam source 70, and (2) a focusing lens 46.

In the first specific configuration of illumination unit 26 inelectro-optical transmission module 24 of electro-optical inspectiondevice 10, illumination unit 26 ‘does not include’ components, inparticular, a polarizing beam splitter 48, at least one strategicallylocated operatively coupled optical feedback reference beam detector 74and illumination unit temperature sensor, TS_(i), 78, and associatedelectro-optical feedback circuitry, and, sub-steps and procedures,implemented via corresponding algorithms and software programs, foroperating thereof, for monitoring temperature and compensating fortemperature changes in critical regions of operation of illuminationunit 26 in electro-optical transmission module 24 of electro-opticalinspection device 10.

Electromagnetic radiation beam source 70 generates and emitselectromagnetic radiation source beam 44. Electromagnetic radiation beamsource 70 is any appropriately compact or miniature sized and configureddevice, mechanism, or component, capable of generating and emitting anelectromagnetic radiation source beam 44. Electromagnetic radiation beamsource 70 is of structure and functions according to either lightemitting diode (LED) technology, or fiber optic technology. For example,electromagnetic radiation beam source 70 is a light emitting diode(LED). Alternatively, electromagnetic radiation beam source 70 is anoperative combination, for example, an integral device, of anelectromagnetic radiation beam generator, for example, a lamp or alaser, and a fiber optic conductor or fiber optic guide.

In general, electromagnetic radiation source beam 44 generated andemitted by electromagnetic radiation beam source 70 is infraredradiation, visible light, or ultraviolet radiation. Preferably, forelectro-optically inspecting and determining internal properties andcharacteristics, such as density, structure, defects, and impurities,and variabilities thereof, of a volumetric segment 34 of moving rod ofmaterial 12 being a cigarette rod, consisting of processed tobaccoinside a rolled and sealed tube of cigarette wrapping paper,electromagnetic radiation source beam 44 is infrared radiation havingwavelength in the range of between about 900 nm and about 1000 nm, andmore preferably, having wavelength in the range of between about 920 nmand about 970 nm.

Focusing lens 46 is for focusing electromagnetic radiation source beam44, for forming focused beam 28. In the first specific configuration ofillumination unit 26 in electro-optical transmission module 24 ofelectro-optical inspection device 10, ‘without inclusion’ of apolarizing beam splitter 48 and other components of a temperature changemonitoring and compensating electro-optical feedback loop inillumination unit 26, focused beam 28 becomes incident focused beam 32,which is transmitted through first side 30 of transparent passageway 22and incident upon volumetric segment 34.

Incident focused beam 32 illuminates volumetric segment 34 of rod ofmaterial 12 longitudinally moving along coaxial optical path 20 withintransparent passageway 22, such that at least part of incident focusedbeam 32 is affected by and transmitted through volumetric segment 34 andthen transmitted through second side 36 of transparent passageway 22,for forming rod material volumetric segment transmitted beam 38. Rodmaterial volumetric segment transmitted beam 38 is detected by adetection unit 40 in electro-optical transmission module 24 ofelectro-optical inspection device 10, for forming a detected rodmaterial volumetric segment transmitted beam 38′ useable for determiningthe internal properties and characteristics of the longitudinally movingrod of material 12, as described in further detail below.

While electro-optically inspecting longitudinally moving rod of material12, temperature changes typically occur in critical regions of operationof illumination unit 26 in electro-optical transmission module 24 ofelectro-optical inspection device 10, particularly in the immediatevicinity of the electro-optically inspected volumetric segment 34 ofmoving rod of material 12. Magnitudes of such temperature changes may besufficiently large so as to significantly increase noise and errorlevels during the illumination process, which may translate tomeaningful decreases in accuracy and precision of the results obtainedfrom the electro-optical inspection process.

For achieving higher sensitivity, signal to noise ratios, accuracy, andprecision, and therefore, overall performance, of illumination unit 26for generating focused beam 28 and incident focused beam 32 ofelectromagnetic radiation, in electro-optical transmission module 24 ofelectro-optical inspection device 10, preferably, illumination unit 26further includes components, in particular, a polarizing beam splitter48, at least one strategically located operatively coupled opticalfeedback reference beam detector 74 and illumination unit temperaturesensor, TS_(i), 78, and associated electro-optical feedback circuitry,and, sub-steps and procedures, implemented via corresponding algorithmsand software programs, for operating thereof, for monitoring temperatureand compensating for temperature changes in critical regions ofoperation of illumination unit 26 in electro-optical transmission module24 of electro-optical inspection device 10. Such critical regions ofoperation are particularly in the immediate vicinity of theelectro-optically inspected volumetric segment 34 of rod of material 12longitudinally moving along optical path 20 within transparentpassageway 22, during the electro-optical inspection process.

Accordingly, in a second specific, more preferred, configuration ofillumination unit 26 in electro-optical transmission module 24 ofelectro-optical inspection device 10, illumination unit 26 includes themain components: (1) electromagnetic radiation beam source 70, and (2)focusing lens 46, and further includes additional main components: (3) apolarizing beam splitter 48, (4) an optical feedback reference beamdetector 74, (5) an optical feedback reference beam signal amplifier 76,(6) an illumination unit temperature sensor, TS_(i), 78, (7) anillumination unit temperature sensor signal amplifier 80, (8) anillumination unit signal comparator 82, (9) a proportional integrated(PI) regulator 84, (10) a current regulator 86, and (11) illuminationunit electro-optical feedback loop component connections and linkages88.

Focusing lens 46, as in the preceding description of the first specificconfiguration of illumination unit 26, is for focusing electromagneticradiation source beam 44, for forming focused beam 28. In the secondspecific configuration of illumination unit 26 in electro-opticaltransmission module 24 of electro-optical inspection device 10, withinclusion of a polarizing beam splitter 48 and the other components,(4)-(11), of a temperature change monitoring and compensatingelectro-optical feedback loop in illumination unit 26, focused beam 28propagates into polarizing beam splitter 48.

Polarizing beam splitter 48 is for splitting focused beam 28 into twoseparate beams, an optical feedback reference beam 72, and incidentfocused beam 32. Optical feedback reference beam 72 is fed back into theelectro-optical circuit of illumination unit 26, via optical feedbackreference beam detector 74, while incident focused beam 32 istransmitted through first side 30 of transparent passageway 22 andincident upon volumetric segment 34, thereby illuminating volumetricsegment 34 of rod of material 12 longitudinally moving along coaxialoptical path 20 within transparent passageway 22.

In general, the area of illumination, or illuminating area, of incidentfocused beam 32, directly originating from focused beam 28 without firstpassing through polarizing beam splitter 48 (in accordance with thefirst specific configuration of illumination unit 26), or originatingfrom focused beam 28 after first passing through polarizing beamsplitter 48 (in accordance with the second specific configuration ofillumination unit 26), is of a variable magnitude, and is selected andused in accordance with the magnitude of the outer or externalcircumferential area of moving rod of material 12, and in accordancewith the magnitude of the average or characteristic diameter of thesmallest particles or substances making up rod of material 12, which areof analytical interest and inspected during the electro-opticalinspection process. The area of illumination, or illuminating area, ofincident focused beam 32 corresponds to the ‘initial or frontal’ area ofmoving rod of material 12 upon which incident focused beam 32 isincident.

In FIG. 1, with reference to reference XYZ coordinate system 50, it isshown that during operation of electro-optical inspection device 10,electromagnetic radiation source beam 44 generated by illumination unit26 is focused, via focusing lens 46, in the negative Y-direction towardsfirst side 30 (in FIG. 1, to be perspectively viewed and understood asfrom above and towards the top side) of transparent passageway 22 and isalso incident, via polarizing beam splitter 48, in the negativeY-direction upon rod of material 12 longitudinally moving in thepositive Z-direction along coaxial optical path 20 within transparentpassageway 22. Incident focused beam 32 illuminates, in the negativeY-direction, volumetric segment 34 of longitudinally moving rod ofmaterial 12. Accordingly, the area of illumination, or illuminatingarea, of incident focused beam 32 corresponds to the ‘initial orfrontal’ area (in FIG. 1, to be perspectively viewed and understood asthe top side area) of volumetric segment 34 upon which incident focusedbeam 32 is incident.

Preferably, the magnitude of the area of illumination, or illuminatingarea, of incident focused beam 32 is less than the magnitude of theouter or external circumferential area of moving rod of material 12, andgreater than the magnitude of the average or characteristic diameter ofthe smallest particles or substances making up rod of material 12, whichare of analytical interest and inspected during the electro-opticalinspection process. For example, preferably, for electro-opticallyinspecting and determining internal properties and characteristics ofvolumetric segments 34 of moving rod of material 12 being a cigaretterod, the magnitude of the area of illumination, or illuminating area, ofincident focused beam 32 is less than the magnitude, typically, on theorder of about 1 cm, of the outer or external circumferential area ofthe cigarette rod, and greater than the magnitude of the average orcharacteristic diameter, typically, on the order of about 4 mm, of thesmallest particles or substances making up the cigarette rod, which areof analytical interest and inspected during the electro-opticalinspection process.

Optical feedback reference beam detector 74 is for detecting andreceiving optical feedback reference beam 72 output from polarizing beamsplitter 48, and converting optical feedback reference beam 72 into acorresponding optical feedback reference beam output signal, which issent back into the electro-optical circuit of illumination unit 26, viaoptical feedback reference beam signal amplifier 76.

Optical feedback reference beam detector 74 is any appropriately compactor miniature sized and configured device, mechanism, or component,capable of detecting and receiving electromagnetic radiation source beam44 generated and emitted according to either light emitting diode (LED)technology, or fiber optic technology, and for converting such adetected and received beam into a corresponding output signal. Forexample, optical feedback reference beam detector 74 is of structure andfunctions as a light receiving type of device, mechanism, component, orelement, such as a phototransistor, a photosensitive transducer, a fiberoptic conductor or guide, or a photoelectric element. For processdesign, process control, and reference purposes, calibration data andinformation correlating a range of values of the input optical feedbackreference beam 72 with a range of values of the corresponding opticalfeedback reference beam output signal, are empirically determined usingstandardized conditions of operating electro-optical transmission module24.

Optical feedback reference beam signal amplifier 76 is for receiving theoptical feedback reference beam output signal sent from optical feedbackreference beam detector 74, and for amplifying the optical feedbackreference beam output signal. The amplified optical feedback referencebeam output signal is then sent to illumination unit signal comparator82.

Illumination unit temperature sensor, TS_(i), 78 is for monitoring andsensing the temperature, typically, in the range of between about 50° C.and 60° C., in the critical region of operation of illumination unit 26.As shown in FIG. 1, such critical region of operation is particularly inthe immediate vicinity of the electro-optically inspected volumetricsegment 34 of rod of material 12 longitudinally moving along opticalpath 20 within transparent passageway 22, during the electro-opticalinspection process. More specifically, the critical region of operationis in the immediate vicinity where incident focused beam 32 istransmitted through first side 30 of transparent passageway 22 andincident upon volumetric segment 34, for illuminating volumetric segment34 of rod of material 12 longitudinally moving along coaxial opticalpath 20 within transparent passageway 22.

Illumination unit temperature sensor, TS_(i), 78 generates anillumination unit temperature sensor output signal proportional to thesensed temperature in the critical region of operation of illuminationunit 26, and sends the illumination unit temperature sensor outputsignal back into the electro-optical circuit, herein, also referred toas the electro-optical feedback loop, of illumination unit 26, viaillumination unit temperature sensor signal amplifier 80. In general,illumination unit temperature sensor, TS_(i), 78 is any appropriatelycompact or miniature sized and configured temperature sensing device,mechanism, or component, for example, a thermocouple, capable of sensingtemperature, and generating an electrical or electronic signalcorresponding and proportional to the sensed temperature. For processdesign, process control, and reference purposes, calibration data andinformation correlating a range of values of the input sensedtemperature with a corresponding range of values of the correspondingillumination unit temperature sensor output signal, are empiricallydetermined using standardized conditions of operating electro-opticaltransmission module 24.

Illumination unit temperature sensor signal amplifier 80 is forreceiving the illumination unit temperature sensor output signal sentfrom illumination unit temperature sensor, TS_(i), 78, and foramplifying the illumination unit temperature sensor output signal. Theamplified illumination unit temperature sensor output signal is sent toillumination unit signal comparator 82.

Illumination unit signal comparator 82 is for receiving the amplifiedoptical feedback reference beam output signal sent from optical feedbackreference beam signal amplifier 76, and for receiving the amplifiedillumination unit temperature sensor output signal sent fromillumination unit temperature sensor signal amplifier 80. Illuminationunit signal comparator 82 then compares, and adds or subtracts, in acompensative manner, the value of the amplified illumination unittemperature sensor output signal, to or from, respectively, the value ofthe amplified optical feedback reference beam output signal, accordingto the magnitude and the direction or sign (positive or negative) of thetemperature change represented by the amplified illumination unittemperature sensor output signal, for generating an illumination unitsignal comparator output signal, which is sent to proportionalintegrated (PI) regulator 84.

Proportional integrated (PI) regulator 84 is for receiving theillumination unit signal comparator output signal sent from illuminationunit signal comparator 82, and for generating a proportional integrated(PI) regulator output signal, which is sent to current regulator 86.

Current regulator 86 is for receiving the proportional integrated (PI)regulator output signal sent from proportional integrated (PI) regulator84, and for generating a current regulator output signal, which is sentto electromagnetic radiation beam source 70. In proportion to themagnitude of the proportional integrated (PI) regulator output signal,the current regulator output signal regulates, in a temperaturecompensative manner, the level of current used by electromagneticradiation beam source 70, and therefore, regulates, in a temperaturecompensative manner, the generation and emission, via regulatingwavelength or frequency, and intensity or power, of electromagneticradiation source beam 44 by electromagnetic radiation beam source 70.For process design, process control, and reference purposes, calibrationdata and information correlating a range of values of the inputproportional integrated (PI) regulator signal with a corresponding rangeof values of the corresponding current regulator output signal, areempirically determined using standardized conditions of operatingelectro-optical transmission module 24.

Illumination unit electro-optical feedback loop component connectionsand linkages 88 are for operatively connecting and linking thecomponents, in particular, (1) electromagnetic radiation beam source 70,(4) optical feedback reference beam detector 74, (5) optical feedbackreference beam signal amplifier 76, (6) illumination unit temperaturesensor, TS_(i), 78, (7) illumination unit temperature sensor signalamplifier 80, (8) illumination unit signal comparator 82, (9)proportional integrated (PI) regulator 84, and (10) current regulator86, included in the second specific configuration of illumination unit26 in electro-optical transmission module 24 of electro-opticalinspection device 10, in the form of an electro-optical feedback loop,based on monitoring and compensating for temperature changes.

In the second specific configuration of illumination unit 26 inelectro-optical transmission module 24 of electro-optical inspectiondevice 10, the regulatory, temperature compensative, action performed byproportional integrated (PI) regulator 84 and current regulator 86 isbased upon, and in accordance with, operation of the strategicallylocated operatively coupled optical feedback reference beam detector 74and temperature sensor, TS_(i), 78, and associated electro-opticalfeedback circuitry, included in illumination unit 26, involving theillumination unit temperature sensor output signal sent by illuminationunit temperature sensor 78, which in turn, is proportional to the sensedtemperature in the critical region of operation of illumination unit 26.Thus, overall operation of illumination unit 26 is based on, and inaccordance with, a temperature change monitoring and compensatingelectro-optical feedback loop.

Automatic operations of illumination unit 26, in general, and of theabove described electrical and electronic components and elementsthereof, in electro-optical transmission module 24 of electro-opticalinspection device 10, are performed by a process control and dataanalysis unit, such as process control and data analysis unit 120.

In Step (d), there is detecting the rod material volumetric segmenttransmitted beam by a detection unit of the electro-optical transmissionmodule, for forming a detected rod material volumetric segmenttransmitted beam useable for determining the internal properties andcharacteristics of the longitudinally moving rod of material.

As described above, according to operation of either the first or secondspecific configuration of illumination unit 26 in electro-opticaltransmission module 24 of electro-optical inspection device 10, incidentfocused beam 32 illuminates volumetric segment 34 of longitudinallymoving rod of material 12, such that at least part of incident focusedbeam 32 is affected by and transmitted through volumetric segment 34 andthen transmitted through second side 36 of transparent passageway 22,for forming rod material volumetric segment transmitted beam 38. Inelectro-optical transmission module 24 of electro-optical inspectiondevice 10, detection unit 40 is for detecting rod material volumetricsegment transmitted beam 38, for forming a detected rod materialvolumetric segment transmitted beam 38′ useable for determining theinternal properties and characteristics of the longitudinally moving rodof material 12.

In a first specific configuration of detection unit 40 inelectro-optical transmission module 24 of electro-optical inspectiondevice 10, detection unit 40 includes the main components: (1) atransmitted beam first detector 90, (2) a transmitted beam seconddetector 92, (3) a transmitted beam signal first amplifier 94, (4) atransmitted beam signal second amplifier 96, (5) a detection unit signalintegrator 98, (6) a detection unit signal buffer 106, and (7) detectionunit component connections and linkages 108.

In the first specific configuration of detection unit 40 inelectro-optical transmission module 24 of electro-optical inspectiondevice 10, detection unit 40 ‘does not include’ components, inparticular, at least one strategically located detection unittemperature sensor, TS_(d), 100 and an operatively coupled detectionunit signal comparator 104, and associated electro-optical circuitry,and, sub-steps and procedures, implemented via corresponding algorithmsand software programs, for operating thereof, for monitoring temperatureand compensating for temperature changes in critical regions ofoperation of detection unit 40 in electro-optical transmission module 24of electro-optical inspection device 10.

Transmitted beam first detector 90 and transmitted beam second detector92 are for detecting and receiving rod material volumetric segmenttransmitted beam 38 which is transmitted from volumetric segment 34 andthen transmitted through second side 36 of transparent passageway 22,for forming detected rod material volumetric segment transmitted beam38′. Transmitted beam first and second detectors 90 and 92,respectively, each convert part of detected rod material volumetricsegment transmitted beam 38′ into a corresponding detected rod materialvolumetric segment transmitted beam output signal, which is sent totransmitted beam signal first and second amplifiers 94 and 96,respectively.

Each of transmitted beam first and second detector 90 and 92 is anyappropriately compact or miniature sized and configured device,mechanism, or component, capable of detecting and receiving rod materialvolumetric segment transmitted beam 38, and for converting such adetected and received beam into a corresponding output signal. Forexample, each of transmitted beam first and second detector 90 and 92 isof structure and functions as a light receiving type of device,mechanism, component, or element, such as a phototransistor, aphotosensitive transducer, a fiber optic conductor or guide, or aphotoelectric element. For process design, process control, andreference purposes, calibration data and information correlating a rangeof values of the input rod material volumetric segment transmitted beam38 with a range of values of the corresponding detected rod materialvolumetric segment transmitted beam output signals, are empiricallydetermined using standardized conditions of operating electro-opticaltransmission module 24.

Transmitted beam signal first amplifier 94 and transmitted beam signalsecond amplifier 96, are each for receiving a corresponding detected rodmaterial volumetric segment transmitted beam output signal, sent fromtransmitted beam first and second detectors 90 and 92, respectively, andfor amplifying the corresponding detected rod material volumetricsegment transmitted beam output signal. The corresponding amplifieddetected rod material volumetric segment transmitted beam output signalsare then sent to detection unit signal integrator 98.

Detection unit signal integrator 98 is for receiving, and integratingthe values of, the corresponding amplified detected rod materialvolumetric segment transmitted beam output signals sent from transmittedbeam signal first and second amplifiers 94 and 96, respectively, forforming a detection unit signal integrator output signal. In the firstspecific configuration of detection unit 40 in electro-opticaltransmission module 24 of electro-optical inspection device 10, ‘withoutinclusion’ of at least one strategically located detection unittemperature sensor, TS_(d), 100 and an operatively coupled detectionunit signal comparator 104 as part of a temperature change monitoringand compensating electro-optical sub-circuit, detection unit signalintegrator output signal is directly sent to detection unit outputsignal buffer 106.

Detection unit output signal buffer 106, in the first specificconfiguration of detection unit 40 in electro-optical transmissionmodule 24 of electro-optical inspection device 10, is for directlyreceiving the detection unit signal integrator output signal sent fromdetection unit signal integrator 98, and storing the detection unitsignal integrator output signal in the form of a stored detection unitoutput signal 106′. Stored detection unit output signal 106′ is sent toa process control and data analysis unit, for example, process controland data analysis unit 120, as shown in FIG. 1, for determining theinternal properties and characteristics, such as density, structure,defects, and impurities, and variabilities thereof, of longitudinallymoving rod of material 12. The determined internal properties andcharacteristics of moving rod of material 12 are useable by a processcontrol and data analysis unit, for example, process control and dataanalysis unit 120, for controlling the process of electro-opticallyinspecting moving rod of material 12, and/or for controlling downstreamprocessing of longitudinally moving rod of material 12.

Detection unit component connections and linkages 108 in the firstspecific configuration of detection unit 40 in electro-opticaltransmission module 24 of electro-optical inspection device 10, are foroperatively connecting and linking the components, in particular, (1)transmitted beam first detector 90, (2) transmitted beam second detector92, (3) transmitted beam signal first amplifier 94, (4) transmitted beamsignal second amplifier 96, (5) detection unit signal integrator 98, and(6) detection unit signal buffer 106, which are included in the firstspecific configuration of detection unit 40.

While electro-optically inspecting longitudinally moving rod of material12, temperature changes typically occur in critical regions of operationof detection unit 40 in electro-optical transmission module 24 ofelectro-optical inspection device 10, particularly in the immediatevicinity of the electro-optically inspected volumetric segment 34 ofmoving rod of material 12. Magnitudes of such temperature changes may besufficiently large so as to significantly increase noise and errorlevels during the detection (data collection and measurement) process,which may translate to meaningful decreases in accuracy and precision ofthe results obtained from the electro-optical inspection process.

For achieving higher sensitivity, signal to noise ratios, accuracy, andprecision, and therefore, overall performance, of detection unit 40 fordetecting rod material volumetric segment transmitted beam 38 ofelectromagnetic radiation, in electro-optical transmission module 24 ofelectro-optical inspection device 10, preferably, detection unit 40further includes components, in particular, at least one strategicallylocated detection unit temperature sensor, TS_(d), 100 and anoperatively coupled detection unit signal comparator 104, and associatedelectro-optical circuitry, and, sub-steps and procedures, implementedvia corresponding algorithms and software programs, for operatingthereof, for monitoring temperature and compensating for temperaturechanges in critical regions of operation of detection unit 26 inelectro-optical transmission module 24 of electro-optical inspectiondevice 10. Such critical regions of operation are particularly in theimmediate vicinity of the electro-optically inspected volumetric segment34 of rod of material 12 longitudinally moving along optical path 20within transparent passageway 22, during the electro-optical inspectionprocess.

Accordingly, in a second specific, more preferred, configuration ofdetection unit 40 in electro-optical transmission module 24 ofelectro-optical inspection device 10, detection unit 40 includes themain components: (1) transmitted beam first detector 90, (2) transmittedbeam second detector 92, (3) transmitted beam signal first amplifier 94,(4) transmitted beam signal second amplifier 96, (5) detection unitsignal integrator 98, (6) detection unit signal buffer 106, and (7)detection unit component connections and linkages 108, and furtherincludes additional main components: (8) a detection unit temperaturesensor, TS_(d), 100, (9) a detection unit temperature sensor signalamplifier 102, and (10) a detection unit signal comparator 104.

Detection unit signal integrator 98, as in the preceding description ofthe first specific configuration of detection unit 40, is for receiving,and integrating the values of, the corresponding amplified detected rodmaterial volumetric segment transmitted beam output signals sent fromtransmitted beam signal first and second amplifiers 94 and 96,respectively, for forming a detection unit signal integrator outputsignal. In the second specific configuration of detection unit 40 inelectro-optical transmission module 24 of electro-optical inspectiondevice 10, with inclusion of at least one strategically locateddetection unit temperature sensor, TS_(d), 100 and an operativelycoupled detection unit signal comparator 104 as part of a temperaturechange monitoring and compensating electro-optical sub-circuit,detection unit signal integrator output signal is sent to detection unitsignal comparator 104.

Detection unit temperature sensor, TS_(d), 100, is for monitoring andsensing the temperature, typically, in the range of between about 50° C.and 60° C., in the critical region of operation of detection unit 40. Asshown in FIG. 1, such critical region of operation is particularly inthe immediate vicinity of the electro-optically inspected volumetricsegment 34 of rod of material 12 longitudinally moving along opticalpath 20 within transparent passageway 22, during the electro-opticalinspection process. More specifically, the critical region of operationis in the immediate vicinity where rod material volumetric segmenttransmitted beam 38 is transmitted from volumetric segment 34 and thentransmitted through second side 36 of transparent passageway 22, andthen detected and received by transmitted beam first and seconddetectors 90 and 92, for forming detected rod material volumetricsegment transmitted beam 38′.

Detection unit temperature sensor, TS_(d), 100, generates a detectionunit temperature sensor output signal proportional to the sensedtemperature in the critical region of operation of detection unit 40,and sends the detection unit temperature sensor output signal todetection unit temperature sensor signal amplifier 102. In general,detection unit temperature sensor, TS_(d), 100, is any appropriatelycompact or miniature sized and configured temperature sensing device,mechanism, or component, for example, a thermocouple, capable of sensingtemperature, and generating an electrical or electronic signalcorresponding and proportional to the sensed temperature. For processdesign, process control, and reference purposes, calibration data andinformation correlating a range of values of the input sensedtemperature with a corresponding range of values of the correspondingdetection unit temperature sensor output signal, are empiricallydetermined using standardized conditions of operating electro-opticaltransmission module 24.

Detection unit temperature sensor signal amplifier 102 is for receivingthe detection unit temperature sensor output signal sent from detectionunit temperature sensor, TS_(d), 100, and for amplifying the detectionunit temperature sensor output signal. The amplified detection unittemperature sensor output signal is sent to detection unit signalcomparator 104.

Detection unit signal comparator 104 is for receiving the amplifieddetection unit temperature sensor output signal sent from detection unittemperature sensor signal amplifier 102, and for receiving the detectionunit signal integrator output signal sent from detection unit signalintegrator 98. Detection unit signal comparator 104 then compares, andadds or subtracts, in a temperature compensative manner, the value ofthe amplified detection unit temperature sensor output signal, to orfrom, respectively, the value of the detection unit signal integratoroutput signal, according to the magnitude and the direction or sign(positive or negative) of the temperature change represented by theamplified detection unit temperature sensor output signal, forgenerating a detection unit signal comparator output signal, herein,also referred to as a detection unit temperature change compensatedoutput signal, which is sent to detection unit output signal buffer 106.

Detection unit output signal buffer 106, in the second specificconfiguration of detection unit 40 in electro-optical transmissionmodule 24 of electro-optical inspection device 10, receives thedetection unit signal comparator output signal (detection unittemperature change compensated output signal) sent from detection unitsignal comparator 104, and stores the detection unit signal comparatoroutput signal (detection unit temperature change compensated outputsignal) in the form of a stored detection unit temperature changecompensated output signal 106′. Stored detection unit temperature changecompensated output signal 106′ is sent to a process control and dataanalysis unit, for example, process control and data analysis unit 120,as shown in FIG. 1, for determining the internal properties andcharacteristics, such as density, structure, defects, and impurities,and variabilities thereof, of longitudinally moving rod of material 12.The determined internal properties and characteristics of moving rod ofmaterial 12 are useable by a process control and data analysis unit, forexample, process control and data analysis unit 120, for controlling theprocess of electro-optically inspecting moving rod of material 12,and/or for controlling downstream processing of longitudinally movingrod of material 12.

Detection unit component connections and linkages 108 in the secondspecific configuration of detection unit 40 in electro-opticaltransmission module 24 of electro-optical inspection device 10, are foroperatively connecting and linking the components, in particular, (1)transmitted beam first detector 90, (2) transmitted beam second detector92, (3) transmitted beam signal first amplifier 94, (4) transmitted beamsignal second amplifier 96, (5) detection unit signal integrator 98, (6)detection unit signal buffer 106, and additional components, (8)detection unit temperature sensor, TS_(d), 100, (9) detection unittemperature sensor signal amplifier 102, and (10) detection unit signalcomparator 104, included in the second specific configuration ofdetection unit 40, in the form of an electro-optical detection circuitwhich includes monitoring and compensating for temperature changes.

In the second specific configuration of detection unit 40 inelectro-optical transmission module 24 of electro-optical inspectiondevice 10, the additional components, (8) detection unit temperaturesensor, TS_(d), 100, (9) detection unit temperature sensor signalamplifier 102, and (10) detection unit signal comparator 104, form atemperature change monitoring and compensating electro-optical detectionsub-circuit, based upon, and in accordance with, operation of thestrategically located detection unit temperature sensor, TS_(d), 100 andoperatively coupled detection unit signal comparator 104, and associatedelectro-optical circuitry, included in detection unit 40, involving thedetection unit temperature sensor output signal sent by detection unittemperature sensor, TS_(d), 100, which in turn, is proportional to thesensed temperature in the critical region of operation of detection unit40. Thus, overall operation of detection unit 40 is based on, and inaccordance with, a temperature change monitoring and compensatingelectro-optical detection circuit.

Automatic operations of detection unit 40, in general, and of the abovedescribed electrical and electronic components and elements thereof, inelectro-optical transmission module 24 of electro-optical inspectiondevice 10, are performed by a process control and data analysis unit,such as process control and data analysis unit 120.

In FIG. 1, with reference to reference XYZ coordinate system 50, it isshown that electro-optical inspection device 10, in general, includingillumination unit 26, detection unit 40, and preferably, a modulehousing 42 of selected components of these units, of electro-opticaltransmission module 24, in particular, are geometrically configured,positioned, and operative, such that electromagnetic radiation sourcebeam 44 generated by illumination unit 26 is focused, via focusing lens46, for example, in the negative Y-direction towards first side 30(perspectively viewed and understood as towards the top side) oftransparent passageway 22 and is also incident, via polarizing beamsplitter 48, for example, in the negative Y-direction upon rod ofmaterial 12 longitudinally moving in the positive Z-direction alongcoaxial optical path 20 within transparent passageway 22.

Accordingly, incident focused beam 32 illuminates, in the negativeY-direction, volumetric segment 34 of longitudinally moving rod ofmaterial 12, such that at least part of incident focused beam 32 isaffected by and transmitted in the negative Y-direction throughvolumetric segment 34, and then transmitted in the negative Y-directionthrough second side 36 (perspectively viewed and understood as throughthe bottom side) of transparent passageway 22, for forming rod materialvolumetric segment transmitted beam 38. Rod material volumetric segmenttransmitted beam 38 is detected by detection unit 40, for formingdetected rod material volumetric segment transmitted beam 38′ useablefor determining the internal properties and characteristics of thelongitudinally moving rod of material 12.

Following are illustratively described the steps and sub-steps of thegeneralized method, and the components, elements, operation, andimplementation, of the generalized electro-optical inspection device, ofthe present invention, with reference to the second exemplary specificpreferred embodiment of the generalized electro-optical inspectiondevice, electro-optical inspection device 60, of the present invention,as illustrated in FIG. 2.

In Step (a), there is guiding the longitudinally moving rod of materialalong its longitudinal axis by a rod guiding unit, along an optical pathwithin a transparent passageway, the optical path and the transparentpassageway coaxially extend along the longitudinal axis of the movingrod of material and pass through an electro-optical transmission module.

In the second exemplary specific preferred embodiment of the generalizeddevice for electro-optically inspecting and determining internalproperties and characteristics of a longitudinally moving rod ofmaterial, that is, moving rod of material 12, as illustrated in FIG. 2,electro-optical inspection device 60 includes the main components: (a) arod guiding unit 14, and (b) a plurality of two electro-opticaltransmission modules 24 a and 24 b.

In electro-optical inspection device 60, rod guiding unit 14 guidesmoving rod of material 12 along its longitudinal axis, extending betweenrod material entrance area 16 and rod material exit area 18 ofelectro-optical inspection device 60, along an optical path 20 (in FIG.2, indicated by the dotted line 20 drawn along the length of moving rodof material 12) within a transparent passageway 22, where optical path20 and transparent passageway 22 coaxially extend along the longitudinalaxis of moving rod of material 12. Preferably, rod guiding unit 14 isoperatively connected to a rod moving unit, such as rod moving unit 5,for example, via rod material entrance area 16, for receivinglongitudinally moving rod of material 12 provided and supplied by rodmoving unit 5.

Rod guiding unit 14 includes the main components: (i) a transparenthousing 62, and (ii) a rod material entrance assembly 64.

Transparent housing 62 houses, holds, or confines, transparentpassageway 22 within which is coaxial optical path 20, along which isguided longitudinally moving rod of material 12. Transparent housing 62is, preferably, of a hollow tubular or cylindrical geometrical shape,and constructed from an optically transparent material, for example, aplastic, a glass, a transparent composite material, or a combinationthereof.

Rod material entrance assembly 64 is operatively attached or connectedto transparent housing 62, and functions as an entrance for thelongitudinally moving rod of material 12 entering into electro-opticalinspection device 10, via rod material entrance area 16. Preferably, rodmaterial entrance assembly 64 is operatively connected to a rod movingunit, such as rod moving unit 5, thereby enabling operative connectionof rod guiding unit 14 with rod moving unit 5. Rod material entranceassembly 64 is preferably of a mostly hollow tubular or cylindricalgeometrical shape, and constructed from a metallic material, anon-metallic material, a composite material, or a combination thereof,for enabling operative attachment or connection to transparent housing62 and for enabling guiding of the moving rod of material 12 along itslongitudinal axis along optical path 20 within coaxial transparentpassageway 22.

For proper implementation of the electro-optical inspection method andelectro-optical inspection device 60, the optically transparent materialof transparent housing 62 in rod guiding unit 14 is compatible with theproperties, characteristics, and operation, of each illumination unit 26a and 26 b. Especially, regarding wavelength or frequency, and intensityor power, of electromagnetic radiation source beams 44 a and 44 bgenerated by illumination units 26 a and 26 b, respectively, such thatfocused beams 28 a and 28 b, respectively, are transmittable throughfirst sides 30 a and 30 b, respectively, of transparent passageway 22and subsequently incident upon volumetric segments 34 a and 34 b,respectively, of rod of material 12 longitudinally moving withintransparent passageway 22.

Moreover, this compatibility is such that subsequent to incident focusedbeams 32 a and 32 b, respectively, illuminating volumetric segments 34 aand 34 b, respectively, of moving rod of material 12, and subsequent toat least part of incident focused beams 32 a and 32 b, respectively,being affected by and transmitted through volumetric segments 34 a and34 b, respectively, the affected incident focused beam exitingvolumetric segments 34 a and 34 b, respectively, is then transmittablethrough second sides 36 a and 36 b, respectively, of transparentpassageway 22, for forming rod material volumetric segment transmittedbeams 38 a and 38 b, respectively. This in turn, enables detection ofrod material volumetric segment transmitted beams 38 a and 38 b,respectively, for forming detected rod material volumetric segmenttransmitted beams 38′a and 38′b, respectively, useable for determiningthe internal properties and characteristics of the longitudinally movingrod of material 12.

In Step (b), there is generating a focused beam of electromagneticradiation by an illumination unit of the electro-optical transmissionmodule, such that the focused beam is transmitted through a first sideof the transparent passageway and incident upon the rod of materiallongitudinally moving within the transparent passageway. In Step (c),there is illuminating a volumetric segment of the longitudinally movingrod of material by the incident focused beam, such that at least part ofthe incident focused beam is affected by and transmitted through thevolumetric segment and then transmitted through a second side of thetransparent passageway, for forming a rod material volumetric segmenttransmitted beam.

In electro-optical inspection device 60, as illustrated in FIG. 2, eachelectro-optical transmission module 24 a and 24 b through which passoptical path 20 and transparent passageway 22, includes the maincomponents: (i) an illumination unit 26 a and 26 b, respectively, and(ii) a detection unit 40 a and 40 b, respectively.

Each illumination unit 26 a and 26 b, respectively, generates a focusedbeam 28 a and 28 b, respectively, of electromagnetic radiation, suchthat focused beam 28 a and 28 b, respectively, is transmitted through afirst side 30 a and 30 b, respectively, of transparent passageway 22 andincident upon rod of material 12 longitudinally moving withintransparent passageway 22, and the incident focused beam 32 a and 32 b,respectively, illuminates a volumetric segment 34 a and 34 b,respectively, of longitudinally moving rod of material 12, such that atleast part of incident focused beam 32 a and 32 b, respectively, isaffected by and transmitted through volumetric segment 34 a and 34 b,respectively, and then transmitted through a second side 36 a and 36 b,respectively, of transparent passageway 22, for forming a rod materialvolumetric segment transmitted beam 38 a and 38 b, respectively.

In a first specific configuration of each illumination unit 26 a and 26b in electro-optical transmission module 24 a and 24 b, respectively, ofelectro-optical inspection device 60, each illumination unit 26 a and 26b, respectively, includes the main components: (1) an electromagneticradiation beam source 70 a and 70 b, respectively, and (2) a focusinglens 46 a and 46 b, respectively.

In the first specific configuration of each illumination unit 26 a and26 b in electro-optical transmission module 24 a and 24 b, respectively,of electro-optical inspection device 60, each illumination unit 26 a and26 b, respectively, ‘does not include’ components, in particular, apolarizing beam splitter 48 a and 48 b, respectively, at least onestrategically located operatively coupled optical feedback referencebeam detector 74 a and 74 b, respectively, and illumination unittemperature sensor, TS_(i), 78 a and 78 b, respectively, and associatedelectro-optical feedback circuitry, and, sub-steps and procedures,implemented via corresponding algorithms and software programs, foroperating thereof, for monitoring temperature and compensating fortemperature changes in critical regions of operation of illuminationunit 26 a and 26 b in electro-optical transmission module 24 a and 24 b,respectively, of electro-optical inspection device 60.

Each electromagnetic radiation beam source 70 a and 70 b, respectively,generates and emits an electromagnetic radiation source beam 44 a and 44b, respectively. Electromagnetic radiation beam source 70 a and 70 b,respectively, is any appropriately compact or miniature sized andconfigured device, mechanism, or component, capable of generating andemitting an electromagnetic radiation source beam 44 a and 44 b,respectively. Electromagnetic radiation beam source 70 a and 70 b,respectively, is of structure and functions according to either lightemitting diode (LED) technology, or fiber optic technology. For example,electromagnetic radiation beam source 70 a and 70 b, respectively, is alight emitting diode (LED). Alternatively, electromagnetic radiationbeam source 70 a and 70 b, respectively, is an operative combination,for example, an integral device, of an electromagnetic radiation beamgenerator, for example, a lamp or a laser, and a fiber optic conductoror fiber optic guide.

In general, electromagnetic radiation source beam 44 a and 44 b,respectively, generated and emitted by electromagnetic radiation beamsource 70 a and 70 b, respectively, is infrared radiation, visiblelight, or ultraviolet radiation. Preferably, for electro-opticallyinspecting and determining internal properties and characteristics, suchas density, structure, defects, and impurities, and variabilitiesthereof, of a volumetric segment 34 a and 34 b, respectively, of movingrod of material 12 being a cigarette rod, consisting of processedtobacco inside a rolled and sealed tube of cigarette wrapping paper,electromagnetic radiation source beam 44 a and 44 b, respectively, isinfrared radiation having wavelength in the range of between about 900nm and about 1000 nm, and more preferably, having wavelength in therange of between about 920 nm and about 970 nm.

Each focusing lens 46 a and 46 b, respectively, focuses electromagneticradiation source beam 44 a and 44 b, respectively, for forming focusedbeam 28 a and 28 b, respectively. In the first specific configuration ofillumination unit 26 a and 26 b in electro-optical transmission module24 a and 24 b, respectively, of electro-optical inspection device 60,‘without inclusion’ of a polarizing beam splitter 48 a and 48 b andother components of a temperature change monitoring and compensatingelectro-optical feedback loop in each illumination unit 26 a and 26 b,respectively, focused beam 28 a and 28 b, respectively, becomes incidentfocused beam 32 a and 32 b, respectively, which is transmitted throughfirst side 30 a and 30 b, respectively, of transparent passageway 22 andincident upon volumetric segment 34 a and 34 b, respectively.

Incident focused beam 32 a and 32 b, respectively, illuminatesvolumetric segment 34 a and 34 b, respectively, of rod of material 12longitudinally moving along coaxial optical path 20 within transparentpassageway 22, such that at least part of incident focused beam 32 a and32 b, respectively, is affected by and transmitted through volumetricsegment 34 a and 34 b, respectively, and then transmitted through secondside 36 a and 36 b, respectively, of transparent passageway 22, forforming rod material volumetric segment transmitted beam 38 a and 38 b,respectively. Rod material volumetric segment transmitted beam 38 a and38 b, respectively, is detected by a detection unit 40 a and 40 b,respectively, in electro-optical transmission module 24 a and 24 b,respectively, of electro-optical inspection device 60, for forming adetected rod material volumetric segment transmitted beam 38′a and 38′b,respectively, useable for determining the internal properties andcharacteristics of the longitudinally moving rod of material 12, asdescribed in further detail below.

While electro-optically inspecting longitudinally moving rod of material12, temperature changes typically occur in critical regions of operationof each illumination unit 26 a and 26 b in electro-optical transmissionmodule 24 a and 24 b, respectively, of electro-optical inspection device60, particularly in the immediate vicinity of each electro-opticallyinspected volumetric segment 34 a and 34 b of moving rod of material 12.Magnitudes of such temperature changes may be sufficiently large so asto significantly increase noise and error levels during the illuminationprocess, which may translate to meaningful decreases in accuracy andprecision of the results obtained from the electro-optical inspectionprocess.

For achieving higher sensitivity, signal to noise ratios, accuracy, andprecision, and therefore, overall performance, of each illumination unit26 a and 26 b, for generating focused beam 28 a and 28 b, respectively,and incident focused beam 32 a and 32 b, respectively, ofelectromagnetic radiation, in each electro-optical transmission module24 a and 24 b of electro-optical inspection device 60, preferably, eachillumination unit 26 a and 26 b further includes components, inparticular, a polarizing beam splitter 48 a and 48 b, respectively, atleast one strategically located operatively coupled optical feedbackreference beam detector 74 a and 74 b, respectively, and illuminationunit temperature sensor, TS_(i), 78 a and 78 b, respectively, andassociated electro-optical feedback circuitry, and, sub-steps andprocedures, implemented via corresponding algorithms and softwareprograms, for operating thereof, for monitoring temperature andcompensating for temperature changes in critical regions of operation ofeach illumination unit 26 a and 26 b of each electro-opticaltransmission module 24 a and 24 b, respectively, of electro-opticalinspection device 60. Such critical regions of operation areparticularly in the immediate vicinity of each electro-opticallyinspected volumetric segment 34 a and 34 b, respectively, of rod ofmaterial 12 longitudinally moving along optical path 20 withintransparent passageway 22, during the electro-optical inspectionprocess.

Accordingly, in a second specific, more preferred, configuration of eachillumination unit 26 a and 26 b in electro-optical transmission module24 a and 24 b, respectively, of electro-optical inspection device 60,each illumination unit 26 a and 26 b includes the main components: (1)electromagnetic radiation beam source 70 a and 70 b, respectively, and(2) focusing lens 46 a and 46 b, respectively, and further includesadditional main components: (3) a polarizing beam splitter 48 a and 48b, respectively, (4) an optical feedback reference beam detector 74 aand 74 b, respectively, (5) an optical feedback reference beam signalamplifier 76 a and 76 b, respectively, (6) an illumination unittemperature sensor, TS_(i), 78 a and 78 b, respectively, (7) anillumination unit temperature sensor signal amplifier 80 a and 80 b,respectively, (8) an illumination unit signal comparator 82 a and 82 b,respectively, (9) a proportional integrated (PI) regulator 84 a and 84b, respectively, (10) a current regulator 86 a and 86 b, respectively,and (11) illumination unit electro-optical feedback loop componentconnections and linkages 88 a and 88 b, respectively.

Focusing lens 46 a and 46 b, respectively, as in the precedingdescription of the first specific configuration of illumination unit 26a and 26 b, respectively, focuses electromagnetic radiation source beam44 a and 44 b, respectively, for forming focused beam 28 a and 28 b,respectively. In the second specific configuration of illumination unit26 a and 26 b in electro-optical transmission module 24 a and 24 b,respectively, of electro-optical inspection device 60, with inclusion ofa polarizing beam splitter 48 a and 48 b and the other components,(4)-(11), of a temperature change monitoring and compensatingelectro-optical feedback loop in each illumination unit 26 a and 26 b,respectively, focused beam 28 a and 28 b propagates into polarizing beamsplitter 48 a and 48 b, respectively.

Polarizing beam splitter 48 a and 48 b, respectively, splits focusedbeam 28 a and 28 b, respectively, into two separate beams, an opticalfeedback reference beam 72 a and 72 b, respectively, and incidentfocused beam 32 a and 32 b, respectively. Optical feedback referencebeam 72 a and 72 b, respectively, is fed back into the electro-opticalcircuit of illumination unit 26 a and 26 b, respectively, via opticalfeedback reference beam detector 74 a and 74 b, respectively, whileincident focused beam 32 a and 32 b, respectively, is transmittedthrough first side 30 a and 30 b, respectively, of transparentpassageway 22 and incident upon volumetric segment 34 a and 34 b,respectively, thereby illuminating volumetric segment 34 a and 34 b,respectively, of rod of material 12 longitudinally moving along coaxialoptical path 20 within transparent passageway 22.

In general, the area of illumination, or illuminating area, of incidentfocused beam 32 a and 32 b, respectively, directly originating fromfocused beam 28 a and 28 b, respectively, without first passing throughpolarizing beam splitter 48 a and 48 b, respectively (in accordance withthe first specific configuration of illumination unit 26 a and 26 b,respectively), or originating from focused beam 28 a and 28 b,respectively, after first passing through polarizing beam splitter 48 aand 48 b, respectively (in accordance with the second specificconfiguration of illumination unit 26 a and 26 b, respectively), is of avariable magnitude, and is selected and used in accordance with themagnitude of the outer or external circumferential area of moving rod ofmaterial 12, and in accordance with the magnitude of the average orcharacteristic diameter of the smallest particles or substances makingup rod of material 12, which are of analytical interest and inspectedduring the electro-optical inspection process. The area of illumination,or illuminating area, of incident focused beam 32 a and 32 b,respectively, corresponds to the initial or frontal area of moving rodof material 12 upon which incident focused beam 32 a and 32 b,respectively, is incident.

In FIG. 2, with reference to reference XYZ coordinate system 50, it isshown that during operation of electro-optical inspection device 60,electromagnetic radiation source beam 44 a generated by illuminationunit 26 a is focused, via focusing lens 46 a, in the negativeY-direction towards first side 30 a (in FIG. 2, to be perspectivelyviewed and understood as from above and towards the top side) oftransparent passageway 22 and is also incident, via polarizing beamsplitter 48 a, in the negative Y-direction upon rod of material 12longitudinally moving in the positive Z-direction along coaxial opticalpath 20 within transparent passageway 22. Incident focused beam 32 ailluminates, in the negative Y-direction, volumetric segment 34 a oflongitudinally moving rod of material 12. Accordingly, the area ofillumination, or illuminating area, of incident focused beam 32 acorresponds to the ‘initial or frontal’ area (in FIG. 2, to beperspectively viewed and understood as the top side area) of volumetricsegment 34 a upon which incident focused beam 32 a is incident.

In a similar manner, in FIG. 2, it is shown that during operation ofelectro-optical inspection device 60, electromagnetic radiation sourcebeam 44 b generated by illumination unit 26 b is focused, via focusinglens 46 b, in the positive X-direction towards first side 30 b (in FIG.2, to be perspectively viewed and understood as from behind and towardsthe back side) of transparent passageway 22 and is also incident, viapolarizing beam splitter 48 b, in the positive X-direction upon rod ofmaterial 12 longitudinally moving in the positive Z-direction alongcoaxial optical path 20 within transparent passageway 22. Incidentfocused beam 32 b illuminates, in the positive X-direction, volumetricsegment 34 b of longitudinally moving rod of material 12. Accordingly,the area of illumination, or illuminating area, of incident focused beam32 b corresponds to the initial or frontal area (in FIG. 1, to beperspectively viewed and understood as the back side area) of volumetricsegment 34 b upon which incident focused beam 32 b is incident.

Preferably, the magnitude of the area of illumination, or illuminatingarea, of incident focused beam 32 a and 32 b, respectively, is less thanthe magnitude of the outer or external circumferential area of movingrod of material 12, and greater than the magnitude of the average orcharacteristic diameter of the smallest particles or substances makingup rod of material 12, which are of analytical interest and inspectedduring the electro-optical inspection process. For example, preferably,for electro-optically inspecting and determining internal properties andcharacteristics of volumetric segments 34 a and 34 b, respectively, ofmoving rod of material 12 being a cigarette rod, the magnitude of thearea of illumination, or illuminating area, of incident focused beam 32a and 32 b, respectively, is less than the magnitude, typically, on theorder of about 1 cm, of the outer or external circumferential area ofthe cigarette rod, and greater than the magnitude of the average orcharacteristic diameter, typically, on the order of about 4 mm, of thesmallest particles or substances making up the cigarette rod, which areof analytical interest and inspected during the electro-opticalinspection process.

Optical feedback reference beam detector 74 a and 74 b, respectively,detects and receives optical feedback reference beam 72 a and 72 b,respectively, output from polarizing beam splitter 48 a and 48 b,respectively, and converts optical feedback reference beam 72 a and 72b, respectively, into a corresponding optical feedback reference beamoutput signal, which is sent back into the electro-optical circuit ofillumination unit 26 a and 26 b, respectively, via optical feedbackreference beam signal amplifier 76 a and 76 b, respectively.

Each optical feedback reference beam detector 74 a and 74 b is anyappropriately compact or miniature sized and configured device,mechanism, or component, capable of detecting and receivingelectromagnetic radiation source beam 44 a and 44 b, respectively,generated and emitted according to either light emitting diode (LED)technology, or fiber optic technology, and for converting such adetected and received beam into a corresponding output signal. Forexample, each optical feedback reference beam detector 74 a and 74 b isof structure and functions as a light receiving type of device,mechanism, component, or element, such as a phototransistor, aphotosensitive transducer, a fiber optic conductor or guide, or aphotoelectric element. For process design, process control, andreference purposes, calibration data and information correlating a rangeof values of the input optical feedback reference beam 72 a and 72 b,respectively, with a range of values of the corresponding opticalfeedback reference beam output signal, are empirically determined usingstandardized conditions of operating electro-optical transmission module24 a and 24 b.

Optical feedback reference beam signal amplifier 76 a and 76 b,respectively, receives the optical feedback reference beam output signalsent from optical feedback reference beam detector 74 a and 74 b,respectively, and amplifies the optical feedback reference beam signal.The amplified optical feedback reference beam signal is then sent toillumination unit signal comparator 82 a and 82 b, respectively.

Illumination unit temperature sensor, TS_(i), 78 a and 78 b,respectively, monitors and senses the temperature, typically, in therange of between about 50° C. and 60° C., in the critical region ofoperation of illumination unit 26 a and 26 b, respectively. As shown inFIG. 2, such critical region of operation is particularly in theimmediate vicinity of the electro-optically inspected volumetric segment34 a and 34 b, respectively, of rod of material 12 longitudinally movingalong optical path 20 within transparent passageway 22, during theelectro-optical inspection process. More specifically, the criticalregion of operation is in the immediate vicinity where incident focusedbeam 32 a and 32 b, respectively, is transmitted through first side 30 aand 30 b, respectively, of transparent passageway 22 and incident uponvolumetric segment 34 a and 34 b, respectively, for illuminatingvolumetric segment 34 a and 34 b, respectively, of rod of material 12longitudinally moving along coaxial optical path 20 within transparentpassageway 22.

Illumination unit temperature sensor, TS_(i), 78 a and 78 b,respectively, generates an illumination unit temperature sensor outputsignal proportional to the sensed temperature in the critical region ofoperation of illumination unit 26 a and 26 b, respectively, and sendsthe illumination unit temperature sensor output signal back into theelectro-optical circuit, herein, also referred to as the electro-opticalfeedback loop, of illumination unit 26 a and 26 b, respectively, viaillumination unit temperature sensor signal amplifier 80 a and 80 b,respectively. In general, illumination unit temperature sensor, TS_(i),78 a and 78 b, respectively, is any appropriately compact or miniaturesized and configured temperature sensing device, mechanism, orcomponent, for example, a thermocouple, capable of sensing temperature,and generating an electrical or electronic signal corresponding andproportional to the sensed temperature. For process design, processcontrol, and reference purposes, calibration data and informationcorrelating a range of values of the input sensed temperature with arange of values of the corresponding illumination unit temperaturesensor output signal, are empirically determined using standardizedconditions of operating electro-optical transmission modules 24 a and 24b.

Illumination unit temperature sensor signal amplifier 80 a and 80 b,respectively, receives the illumination unit temperature sensor outputsignal sent from illumination unit temperature sensor, TS_(i), 78 a and78 b, respectively, and then amplifies the illumination unit temperaturesensor output signal. The amplified illumination unit temperature sensoroutput signal is then sent to illumination unit signal comparator 82 aand 82 b, respectively.

Illumination unit signal comparator 82 a and 82 b, respectively,receives the amplified optical feedback reference beam output signalsent from optical feedback reference beam signal amplifier 76 a and 76b, respectively, and receives the amplified illumination unittemperature sensor output signal sent from illumination unit temperaturesensor signal amplifier 80 a and 80 b, respectively. Illumination unitsignal comparator 82 a and 82 b, respectively, then compares, and addsor subtracts, in a compensative manner, the value of the amplifiedillumination unit temperature sensor output signal, to or from,respectively, the value of the amplified optical feedback reference beamoutput signal, according to the magnitude and the direction or sign(positive or negative) of the temperature change represented by theamplified illumination unit temperature sensor output signal, forgenerating an illumination unit signal comparator output signal, whichis sent to proportional integrated (PI) regulator 84 a and 84 b,respectively.

Proportional integrated (PI) regulator 84 a and 84 b, respectively,receives the illumination unit signal comparator output signal sent fromillumination unit signal comparator 82 a and 82 b, respectively, andgenerates a proportional integrated (PI) regulator output signal, whichis sent to current regulator 86 a and 86 b, respectively.

Current regulator 86 a and 86 b, respectively, receives the proportionalintegrated (PI) regulator output signal sent from proportionalintegrated (PI) regulator 84 a and 84 b, respectively, and generates acurrent regulator output signal, which is sent to electromagneticradiation beam source 70 a and 70 b, respectively. In proportion to themagnitude of the proportional integrated (PI) regulator output signal,the current regulator output signal regulates, in a temperaturecompensative manner, the level of current used by electromagneticradiation beam source 70 a and 70 b, respectively, and therefore,regulates, in a temperature compensative manner, the generation andemission, via regulating wavelength or frequency, and intensity orpower, of electromagnetic radiation source beam 44 a and 44 b,respectively, by electromagnetic radiation beam source 70 a and 70 b,respectively. For process design, process control, and referencepurposes, calibration data and information correlating a range of valuesof the input proportional integrated (PI) regulator signal with acorresponding range of values of the corresponding current regulatoroutput signal, are empirically determined using standardized conditionsof operating electro-optical transmission modules 24 a and 24 b.

Illumination unit electro-optical feedback loop component connectionsand linkages 88 a and 88 b, respectively, operatively connect and linkthe components, in particular, (1) electromagnetic radiation beam source70 a and 70 b, respectively, (4) optical feedback reference beamdetector 74 a and 74 b, respectively, (5) optical feedback referencebeam signal amplifier 76 a and 76 b, respectively, (6) illumination unittemperature sensor, TS_(i), 78 a and 78 b, respectively, (7)illumination unit temperature sensor signal amplifier 80 a and 80 b,respectively, (8) illumination unit signal comparator 82 a and 82 b,respectively, (9) proportional integrated (PI) regulator 84 a and 84 b,respectively, and (10) current regulator 86 a and 86 b, respectively,included in the second specific configuration of illumination unit 26 aand 26 b, respectively, in electro-optical transmission module 24 a and24 b, respectively, of electro-optical inspection device 60, in the formof an electro-optical feedback loop, based on monitoring andcompensating for temperature changes.

In the second specific configuration of illumination unit 26 a and 26 b,respectively, in electro-optical transmission module 24 a and 24 b,respectively, of electro-optical inspection device 60, the regulatory,temperature compensative, action performed by each proportionalintegrated (PI) regulator 84 a and 84 b and current regulator 86 a and86 b, respectively, is based upon, and in accordance with, operation ofthe strategically located operatively coupled optical feedback referencebeam detector 74 a and 74 b, respectively, and temperature sensor,TS_(i), 78 a and 78 b, respectively, and associated electro-opticalfeedback circuitry, included in illumination unit 26 a and 26 b,respectively, involving the illumination unit temperature sensor outputsignal sent by illumination unit temperature sensor 78 a and 78 b,respectively, which in turn, is proportional to the sensed temperaturein the critical region of operation of illumination unit 26 a and 26 b,respectively. Thus, overall operation of each illumination unit 26 a and26 b is based on, and in accordance with, a temperature changemonitoring and compensating electro-optical feedback loop.

Automatic operations of each illumination unit 26 a and 26 b, ingeneral, and of the above described electrical and electronic componentsand elements thereof, in each electro-optical transmission module 24 aand 26 b, respectively, of electro-optical inspection device 60, areperformed by a process control and data analysis unit, such as processcontrol and data analysis unit 120.

In Step (d), there is detecting the rod material volumetric segmenttransmitted beam by a detection unit of the electro-optical transmissionmodule, for forming a detected rod material volumetric segmenttransmitted beam useable for determining the internal properties andcharacteristics of the longitudinally moving rod of material.

As described above, according to operation of either the first or secondspecific configuration of illumination units 26 a and 26 b inelectro-optical transmission module 24 a and 24 b, respectively, ofelectro-optical inspection device 60, incident focused beam 32 a and 32b, respectively, illuminates volumetric segment 34 a and 34 b,respectively, of longitudinally moving rod of material 12, such that atleast part of incident focused beam 32 a and 32 b, respectively, isaffected by and transmitted through volumetric segment 34 a and 34 b,respectively, and then transmitted through second side 36 a and 36 b,respectively, of transparent passageway 22, for forming rod materialvolumetric segment transmitted beam 38 a and 38 b, respectively. In eachelectro-optical transmission module 24 a and 24 b, respectively, ofelectro-optical inspection device 60, detection unit 40 a and 40 b,respectively, detects rod material volumetric segment transmitted beam38 a and 38 b, respectively, and forms a detected rod materialvolumetric segment transmitted beam 38′a and 38′b, respectively, useablefor determining the internal properties and characteristics of thelongitudinally moving rod of material 12.

In a first specific configuration of each detection unit 40 a and 40 bin electro-optical transmission module 24 a and 24 b, respectively, ofelectro-optical inspection device 60, each detection unit 40 a and 40 b,respectively, includes the main components: (1) a transmitted beam firstdetector 90 a and 90 b, respectively, (2) a transmitted beam seconddetector 92 a and 92 b, respectively, (3) a transmitted beam signalfirst amplifier 94 a and 94 b, respectively, (4) a transmitted beamsignal second amplifier 96 a and 96 b, respectively, (5) a detectionunit signal integrator 98 a and 98 b, respectively, (6) a detection unitsignal buffer 106 a and 106 b, respectively, and (7) detection unitcomponent connections and linkages 108 a and 108 b, respectively.

In the first specific configuration of each detection unit 40 a and 40 bin electro-optical transmission module 24 a and 24 b, respectively, ofelectro-optical inspection device 60, each detection unit 40 a and 40 b,respectively, ‘does not include’ components, in particular, at least onestrategically located detection unit temperature sensor, TS_(d), 100 aand 100 b, respectively, and an operatively coupled detection unitsignal comparator 104 a and 104 b, respectively, and associatedelectro-optical circuitry, and, sub-steps and procedures, implementedvia corresponding algorithms and software programs, for operatingthereof, for monitoring temperature and compensating for temperaturechanges in critical regions of operation of each detection unit 40 a and40 b, respectively, in electro-optical transmission module 24 a and 24b, respectively, of electro-optical inspection device 60.

Transmitted beam first detector 90 a and 90 b, respectively, andtransmitted beam second detector 92 a and 92 b, respectively, detect andreceive rod material volumetric segment transmitted beam 38 a and 38 b,respectively, which is transmitted from volumetric segment 34 a and 34b, respectively, and then transmitted through second side 36 a and 36 b,respectively, of transparent passageway 22, for forming detected rodmaterial volumetric segment transmitted beam 38′a and 38′b,respectively. Transmitted beam first detectors 90 a and 90 b,respectively, and transmitted beam second detectors, 92 a and 92 b,respectively, each convert part of detected rod material volumetricsegment transmitted beam 38′a and 38 b′, respectively, into acorresponding detected rod material volumetric segment transmitted beamoutput signal, which is sent to transmitted beam signal first amplifiers94 a and 94 b, respectively, and transmitted beam signal secondamplifiers 96 a and 96 b, respectively.

Each transmitted beam first detector 90 a and 90 b, respectively, andtransmitted beam second detector 92 a and 92 b, respectively, is anyappropriately compact or miniature sized and configured device,mechanism, or component, capable of detecting and receiving rod materialvolumetric segment transmitted beam 38 a and 38 b, respectively, and forconverting such a detected and received beam into a corresponding outputsignal. For example, each of transmitted beam first 90 a and 90 b,respectively, and transmitted beam second detector 92 a and 92 b,respectively, is of structure and functions as a light receiving type ofdevice, mechanism, component, or element, such as a phototransistor, aphotosensitive transducer, a fiber optic conductor or guide, or aphotoelectric element. For process design, process control, andreference purposes, calibration data and information correlating a rangeof values of the input rod material volumetric segment transmitted beam38 a and 38 b, respectively, with a range of values of the correspondingdetected rod material volumetric segment transmitted beam outputsignals, are empirically determined using standardized conditions ofoperating electro-optical transmission module 24 a and 24 b,respectively.

Transmitted beam signal first amplifier 94 a and 94 b, respectively, andtransmitted beam signal second amplifier 96 a and 96 b, respectively,each receive a corresponding detected rod material volumetric segmenttransmitted beam output signal, sent from transmitted beam first andsecond detectors 90 a and 90 b, and, 92 a and 92 b, respectively, andthen amplify the corresponding detected rod material volumetric segmenttransmitted beam output signal. The corresponding amplified detected rodmaterial volumetric segment transmitted beam output signals are thensent to detection unit signal integrators 98 a and 98 b, respectively.

Detection unit signal integrator 98 a and 98 b, respectively, receives,and integrates the values of, the corresponding amplified detected rodmaterial volumetric segment transmitted beam output signals sent fromtransmitted beam signal first and second amplifiers 94 a and 94 b, and,96 a and 96 b, respectively, for forming a detection unit signalintegrator output signal. In the first specific configuration of eachdetection unit 40 a and 40 b in electro-optical transmission module 24 aand 24 b, respectively, of electro-optical inspection device 60,‘without inclusion’ of at least one strategically located detection unittemperature sensor, TS_(d), 100 a and 100 b, respectively, and anoperatively coupled detection unit signal comparator 104 a and 104 b,respectively, as part of a temperature change monitoring andcompensating electro-optical sub-circuit, detection unit signalintegrator output signal is directly sent to detection unit outputsignal buffer 106 a and 106 b, respectively.

Detection unit output signal buffer 106 a and 106 b in the firstspecific configuration of each detection unit 40 a and 40 b,respectively, in electro-optical transmission module 24 a and 24 b,respectively, of electro-optical inspection device 60, directly receivesthe detection unit signal integrator output signal sent from detectionunit signal integrator 98 a and 98 b, respectively, and stores thedetection unit signal integrator output signal in the form of a storeddetection unit output signal 106′a and 106′b, respectively. Storeddetection unit output signal 106′a and 106′b, respectively, is sent to aprocess control and data analysis unit, for example, process control anddata analysis unit 120, as shown in FIG. 2, for determining the internalproperties and characteristics, such as density, structure, defects, andimpurities, and variabilities thereof, of longitudinally moving rod ofmaterial 12. The determined internal properties and characteristics ofmoving rod of material 12 are useable by a process control and dataanalysis unit, for example, process control and data analysis unit 120,for controlling the process of electro-optically inspecting moving rodof material 12, and/or for controlling downstream processing oflongitudinally moving rod of material 12.

Detection unit component connections and linkages 108 a and 108 b,respectively, in the first specific configuration of detection unit 40 aand 40 b, respectively, in electro-optical transmission module 24 a and24 b, respectively, of electro-optical inspection device 60, operativelyconnect and link the components, in particular, (1) transmitted beamfirst detector 90 a and 90 b, respectively, (2) transmitted beam seconddetector 92 a and 92 b, respectively, (3) transmitted beam signal firstamplifier. 94 a and 94 b, respectively, (4) transmitted beam signalsecond amplifier 96 a and 96 b, respectively, (5) detection unit signalintegrator 98 a and 98 b, respectively, and (6) detection unit signalbuffer 106 a and 106 b, respectively, which are included in the firstspecific configuration of detection unit 40 a and 40 b, respectively.

While electro-optically inspecting longitudinally moving rod of material12, temperature changes typically occur in critical regions of operationof each detection unit 40 a and 40 b in electro-optical transmissionmodule 24 a and 24 b, respectively, of electro-optical inspection device60, particularly in the immediate vicinity of each electro-opticallyinspected volumetric segment 34 a and 34 b, respectively, of moving rodof material 12. Magnitudes of such temperature changes may besufficiently large so as to significantly increase noise and errorlevels during the detection (data collection and measurement) process,which may translate to meaningful decreases in accuracy and precision ofthe results obtained from the electro-optical inspection process.

For achieving higher sensitivity, signal to noise ratios, accuracy, andprecision, and therefore, overall performance, of each detection unit 40a and 40 b for detecting rod material volumetric segment transmittedbeam 38 a and 38 b, respectively, of electromagnetic radiation, in eachelectro-optical transmission module 24 a and 24 b of electro-opticalinspection device 60, preferably, each detection unit 40 a and 40 b,respectively, further includes components, in particular, at least onestrategically located detection unit temperature sensor, TS_(d), 100 aand 100 b, respectively, and an operatively coupled detection unitsignal comparator 104 a and 104 b, respectively, and associatedelectro-optical circuitry, and, sub-steps and procedures, implementedvia corresponding algorithms and software programs, for operatingthereof, for monitoring temperature and compensating for temperaturechanges in critical regions of operation of each detection unit 26 a and26 b, respectively, in electro-optical transmission module 24 a and 24b, respectively, of electro-optical inspection device 60. Such criticalregions of operation are particularly in the immediate vicinity of eachelectro-optically inspected volumetric segment 34 a and 34 b,respectively, of rod of material 12 longitudinally moving along opticalpath 20 within transparent passageway 22, during the electro-opticalinspection process.

Accordingly, in a second specific, more preferred, configuration of eachdetection unit 40 a and 40 b in electro-optical transmission module 24 aand 24 b, respectively, of electro-optical inspection device 60, eachdetection unit 40 a and 40 b includes the main components: (1)transmitted beam first detector 90 a and 98 b, respectively, (2)transmitted beam second detector 92 a and 92 b, respectively, (3)transmitted beam signal first amplifier 94 a and 94 b, respectively, (4)transmitted beam signal second amplifier 96 a and 96 b, respectively,(5) detection unit signal integrator 98 a and 98 b, respectively, (6)detection unit signal buffer 106 a and 106 b, respectively, and (7)detection unit component connections and linkages 108 a and 108 b,respectively, and further includes additional main components: (8) adetection unit temperature sensor, TS_(d), 100 a and 100 b,respectively, (9) a detection unit temperature sensor signal amplifier102 a and 102 b, respectively, and (10) a detection unit signalcomparator 104 a and 104 b, respectively.

Detection unit signal integrator 98 a and 98 b, respectively, as in thepreceding description of the first specific configuration of detectionunit 40 a and 40 b, respectively, receives, and integrates the valuesof, the corresponding amplified detected rod material volumetric segmenttransmitted beam output signals sent from transmitted beam signal firstand second amplifiers 94 a and 94 b, and, 96 a and 96 b, respectively,for forming a detection unit signal integrator output signal. In thesecond specific configuration of detection unit 40 a and 40 b,respectively, in electro-optical transmission module 24 a and 24 b,respectively, of electro-optical inspection device 60, with inclusion ofat least one strategically located detection unit temperature sensor,TS_(d), 100 a and 100 b, respectively, and an operatively coupleddetection unit signal comparator 104 a and 104 b, respectively, as partof a temperature change monitoring and compensating electro-opticalsub-circuit, detection unit signal integrator output signal is sent todetection unit signal comparator 104 a and 104 b, respectively.

Detection unit temperature sensor, TS_(d), 100 a and 100 b,respectively, monitors and senses the temperature, typically, in therange of between about 50° C. and 60° C., in the critical region ofoperation of each detection unit 40 a and 40 b, respectively. As shownin FIG. 2, such critical region of operation is particularly in theimmediate vicinity of the electro-optically inspected volumetric segment34 a and 34 b, respectively, of rod of material 12 longitudinally movingalong optical path 20 within transparent passageway 22, during theelectro-optical inspection process. More specifically, the criticalregion of operation is in the immediate vicinity where rod materialvolumetric segment transmitted beam 38 a and 38 b, respectively, istransmitted from volumetric segment 34 a and 34 b, respectively, andthen transmitted through second side 36 a and 36 b, respectively, oftransparent passageway 22, and then detected and received by transmittedbeam first and second detectors 90 a and 90 b, and, 92 a and 92 b,respectively, for forming detected rod material volumetric segmenttransmitted beam 38′a and 38′b, respectively.

Detection unit temperature sensor, TS_(d), 100 a and 100 b,respectively, generates a detection unit temperature sensor outputsignal proportional to the sensed temperature in the critical region ofoperation of detection unit 40 a and 40 b, respectively, and sends thedetection unit temperature sensor output signal to detection unittemperature sensor signal amplifier 102 a and 102 b, respectively. Ingeneral, detection unit temperature sensor, TS_(d), 100 a and 100 b,respectively, is any appropriately compact or miniature sized andconfigured temperature sensing device, mechanism, or component, forexample, a thermocouple, capable of sensing temperature, and generatingan electrical or electronic signal corresponding and proportional to thesensed temperature. For process design, process control, and referencepurposes, calibration data and information correlating a range of valuesof the input sensed temperature with a corresponding range of values ofthe corresponding detection unit temperature sensor output signal, areempirically determined using standardized conditions of operatingelectro-optical transmission module 24 a and 24 b, respectively.

Detection unit temperature sensor signal amplifier 102 a and 102 b,respectively, receives the detection unit temperature sensor outputsignal sent from detection unit temperature sensor, TS_(d), 100 a and100 b, respectively, and amplifies the detection unit temperature sensoroutput signal. The amplified detection unit temperature sensor outputsignal is sent to detection unit signal comparator 104 a and 104 b,respectively.

Detection unit signal comparator 104 a and 104 b, respectively, receivesthe amplified detection unit temperature sensor output signal sent fromdetection unit temperature sensor signal amplifier 102 a and 102 b,respectively, and receives the detection unit signal integrator outputsignal sent from detection unit signal integrator 98 a and 98 b,respectively. Detection unit signal comparator 104 a and 104 b,respectively, then compares, and adds or subtracts, in a temperaturecompensative manner, the value of the amplified detection unittemperature sensor output signal, to or from, respectively, the value ofthe detection unit signal integrator output signal, according to themagnitude and the direction or sign (positive or negative) of thetemperature change represented by the amplified detection unittemperature sensor output signal, for generating a detection unit signalcomparator output signal, herein, also referred to as a detection unittemperature change compensated output signal, which is sent to detectionunit output signal buffer 106 a and 106 b, respectively.

Detection unit output signal buffer 106 a and 106 b, respectively, inthe second specific configuration of detection unit 40 a and 40 b,respectively, in electro-optical transmission module 24 a and 24 b,respectively, of electro-optical inspection device 60, receives thedetection unit signal comparator output signal (detection unittemperature change compensated output signal) sent from detection unitsignal comparator 104 a and 104 b, respectively, and stores thedetection unit signal comparator output signal (detection unittemperature change compensated output signal) in the form of a storeddetection unit temperature change compensated output signal 106′a and106′b, respectively. Stored detection unit temperature changecompensated output signals 106′a and 106′b are sent to a process controland data analysis unit, for example, process control and data analysisunit 120, as shown in FIG. 2, for determining the internal propertiesand characteristics, such as density, structure, defects, andimpurities, and variabilities thereof, of longitudinally moving rod ofmaterial 12. The determined internal properties and characteristics ofmoving rod of material 12 are useable by a process control and dataanalysis unit, for example, process control and data analysis unit 120,for controlling the process of electro-optically inspecting moving rodof material 12, and/or for controlling downstream processing oflongitudinally moving rod of material 12.

Detection unit component connections and linkages 108 a and 108 b,respectively, in the second specific configuration of detection unit 40a and 40 b, respectively, in electro-optical transmission module 24 aand 24 b, respectively, of electro-optical inspection device 60,operatively connect and link the components, in particular, (1)transmitted beam first detector 90 a and 90 b, respectively, (2)transmitted beam second detector 92 a and 92 b, respectively, (3)transmitted beam signal first amplifier 94 a and 94 b, respectively, (4)transmitted beam signal second amplifier 96 a and 96 b, respectively,(5) detection unit signal integrator 98 a and 98 b, respectively, (6)detection unit signal buffer 106 a and 106 b, respectively, andadditional components, (8) detection unit temperature sensor, TS_(d),100 a and 100 b, respectively, (9) detection unit temperature sensorsignal amplifier 102 a and 102 b, respectively, and (10) detection unitsignal comparator 104 a and 104 b, respectively, included in the secondspecific configuration of detection unit 40 a and 40 b, respectively, inthe form of an electro-optical detection circuit which includesmonitoring and compensating for temperature changes.

In the second specific configuration of detection unit 40 a and 40 b,respectively, in electro-optical transmission module 24 a and 24 b,respectively, of electro-optical inspection device 60, the additionalcomponents, (8) detection unit temperature sensor, TS_(d), 100 a and 100b, respectively, (9) detection unit temperature sensor signal amplifier102 a and 102 b, respectively, and (10) detection unit signal comparator104 a and 104 b, respectively, form a temperature change monitoring andcompensating electro-optical detection sub-circuit, based upon, and inaccordance with, operation of the strategically located detection unittemperature sensor, TS_(d), 100 a and 100 b, respectively, andoperatively coupled detection unit signal comparator 104 a and 104 b,respectively, and associated electro-optical circuitry, included indetection unit 40 a and 40 b, respectively, involving the detection unittemperature sensor output signal sent by detection unit temperaturesensor, TS_(d), 100 a and 100 b, respectively, which in turn, isproportional to the sensed temperature in the critical region ofoperation of detection unit 40 a and 40 b, respectively. Thus, overalloperation of each detection unit 40 a and 40 b, respectively, is basedon, and in accordance with, a temperature change monitoring andcompensating electro-optical detection circuit.

Automatic operations of each detection unit 40 a and 40 b, in general,and of the above described electrical and electronic components andelements thereof, in each electro-optical transmission module 24 a and24 b, respectively of electro-optical inspection device 60, areperformed by a process control and data analysis unit, such as processcontrol and data analysis unit 120.

In FIG. 2, with reference to reference XYZ coordinate system 50, it isshown that the first of the two electro-optical transmission modules,that is, electro-optical transmission module 24 a, in general, includingillumination unit 26 a, detection unit 40 a, and preferably, a housing42 a of selected components of these units, of electro-opticalinspection device 60, are geometrically configured, positioned, andoperative, such that electromagnetic radiation source beam 44 agenerated by illumination unit 26 a is focused, via focusing lens 46 a,in the negative Y-direction towards first side 30 a (perspectivelyviewed and understood as from above and towards the top side) oftransparent passageway 22 and is also incident, via polarizing beamsplitter 48 a, in the negative Y-direction upon rod of material 12longitudinally moving in the positive Z-direction along coaxial opticalpath 20 within transparent passageway 22. Accordingly, incident focusedbeam 32 a illuminates, in the negative Y-direction, volumetric segment34 a of longitudinally moving rod of material 12, such that at leastpart of incident focused beam 32 a is affected by and transmitted in thenegative Y-direction through volumetric segment 34 a, and thentransmitted in the negative Y-direction through second side 36 a(perspectively viewed and understood as through the bottom side) oftransparent passageway 22, for forming rod material volumetric segmenttransmitted beam 38 a. Rod material volumetric segment transmitted beam38 a is detected by detection unit 40 a, for forming detected rodmaterial volumetric segment transmitted beam 38′a useable fordetermining the internal properties and characteristics of thelongitudinally moving rod of material 12.

Additionally in FIG. 2, with reference to reference XYZ coordinatesystem 50, it is shown that the second of the two electro-opticaltransmission modules, that is, electro-optical transmission module 24 b,in general, including illumination unit 26 b, detection unit 40 b, andpreferably, a housing 42 b of selected components of these units, ofelectro-optical inspection device 60, are geometrically configured,positioned, and operative, such that electromagnetic radiation sourcebeam 44 b generated by illumination unit 26 b is focused, via focusinglens 46 b, in the positive X-direction towards first side 30 b(perspectively viewed and understood as from behind and towards the backside) of transparent passageway 22 and is also incident, via polarizingbeam splitter 48 b, in the positive X-direction upon rod of material 12longitudinally moving in the positive Z-direction along coaxial opticalpath 20 within transparent passageway 22. Accordingly, incident focusedbeam 32 b illuminates, in the positive X-direction, volumetric segment34 b of longitudinally moving rod of material 12, such that at leastpart of incident focused beam 32 b is affected by and transmitted in thepositive X-direction through volumetric segment 34 a, and thentransmitted in the positive X-direction through second side 36 a(perspectively viewed and understood as through the front side) oftransparent passageway 22, for forming rod material volumetric segmenttransmitted beam 38 b. Rod material volumetric segment transmitted beam38 b is detected by detection unit 40 b, for forming detected rodmaterial volumetric segment transmitted beam 38′b useable fordetermining the internal properties and characteristics of thelongitudinally moving rod of material 12.

As clearly shown in FIG. 2, with reference to reference XYZ coordinatesystem 50, in electro-optical inspection device 60, the longitudinal andangular, radial, or circumferential, positions or locations of the firstand second electro-optical transmission modules 24 a and 24 b, ingeneral, and, of illumination units 26 a and 26 b, detection units 40 aand 40 b, and housings 42 a and 42 b of selected components of theseunits, respectively, in particular, relative to each other, and relativeto the same transparent passageway 22 within which extends the samecoaxial optical path 20, are spatially staggered or displaced along thecoaxial optical path 20, along which the longitudinally moving rod ofmaterial 12 is guided by the rod guiding unit 14.

More specifically, in electro-optical inspection device 60, each of thetwo electro-optical transmission modules 24 a and 24 b, includingrespective units and components thereof, through which passes the samecoaxial optical path 20 and the same coaxial transparent passageway 22,is positioned at a different longitudinal (spatial) position or locationin the Z-direction around and along transparent passageway 22 withinwhich extends coaxial optical path 20. Additionally, at each differentlongitudinal (spatial) position or location in the Z-direction aroundand along transparent passageway 22, each of the two electro-opticaltransmission modules 24 a and 24 b, including respective units andcomponents thereof, is positioned at a different angular, radial, orcircumferential, position or location in the XY-plane around transparentpassageway 22. In the particular embodiment of electro-opticalinspection device 60, illustrated in FIG. 2, at the differentlongitudinal (spatial) positions or locations in the Z-direction aroundand along transparent passageway 22, the angular, radial, orcircumferential, positions or locations of the two electro-opticaltransmission modules 24 a and 24 b, including respective units andcomponents thereof, relative to each other, in the XY-plane aroundtransparent passageway 22, differ by a right angle or 90 degrees.

In electro-optical inspection device 60, spatially staggering ordisplacing the positions or locations of electro-optical transmissionmodules 24 a and 24 b significantly decreases potential crossinterferences among the various electromagnetic radiation beamsemanating from, propagating through, transmitted into, out of, orthrough, and, entering into or exiting out of, illumination units 26 aand 26 b, respectively, first side 30 a and 30 b, respectively, andsecond side 36 a and 36 b, respectively, of transparent passageway 22,volumetric segments 34 a and 34 b, respectively, of moving rod ofmaterial 12, and detection units 40 a and 40 b, respectively, ofelectro-optical transmission modules 24 a and 24 b, respectively.

Additionally, the procedure of spatially staggering or displacingenables each volumetric segment 34 a and 34 b of longitudinally movingrod of material 12 to be inspected for a sufficiently integratableamount of time by illumination unit 26 a/detection unit 40 a pair, andby illumination unit 26 b/detection unit 40 b pair, respectively, ofeach electro-optical transmission module 24 a and 24 b, respectively.These factors contribute to achieving higher speed, sensitivity, signalto noise ratios, accuracy, and precision, and therefore, overallperformance, of the electro-optical inspection method implemented byusing electro-optical inspection device 60, having two electro-opticaltransmission modules 24 a and 24 b, in the second exemplary specificpreferred embodiment illustrated in FIG. 2, compared to usingelectro-optical inspection device 10, having a single electro-opticaltransmission module 24, in the first exemplary specific preferredembodiment illustrated in FIG. 1, of the generalized electro-opticalinspection device for electro-optically inspecting and determininginternal properties and characteristics of the longitudinally moving rodof material 12.

Herein following are illustratively described further details, and,additional, alternative, and optional, features, of the steps andsub-steps of the generalized electro-optical inspection method, and ofthe components, elements, operation, and implementation, of thegeneralized electro-optical inspection device, of the present invention,with reference to the first and second exemplary specific preferredembodiments of the generalized electro-optical inspection device,electro-optical inspection devices 10 and 60, of the present invention,as illustrated in FIGS. 1 and 2, respectively.

In electro-optical inspection devices 10 and 60, of the first and secondexemplary specific preferred embodiments, respectively, of thegeneralized device for electro-optically inspecting and determininginternal properties and characteristics of a longitudinally moving rodof material, that is, longitudinally moving rod of material 12, asillustrated in FIGS. 1 and 2, respectively, each electro-opticaltransmission module (24 in FIG. 1; 24 a and 24 b, respectively, in FIG.2) preferably, further includes: (iii) a module housing (42 in FIG. 1;42 a and 42 b, respectively, in FIG. 2).

Module housing (42 in FIG. 1; 42 a and 42 b, respectively, in FIG. 2),through which passes transparent housing 62 of rod guiding unit 14, isfor operatively supporting or holding transparent housing 62 whichhouses, holds, or confines, transparent passageway 22 within which iscoaxial optical path 20, along which is guided longitudinally moving rodof material 12. In addition to enabling through passage of transparenthousing 62, module housing (42 in FIG. 1; 42 a and 42 b, respectively,in FIG. 2) is for operatively housing or holding selected components ofillumination unit (26 in FIG. 1; 26 a and 26 b, respectively, in FIG. 2)and of detection unit (40 in FIG. 1; 40 a and 40 b, respectively, inFIG. 2). In particular, the additional main components, polarizing beamsplitter (48 in FIG. 1; 48 a and 48 b, respectively, in FIG. 2), opticalfeedback reference beam detector (74 in FIG. 1; 74 a and 74 b,respectively, in FIG. 2), and illumination unit temperature sensor,TS_(i), (78 in FIG. 1; 78 a and 78 b, respectively, in FIG. 2), in thesecond specific configuration of illumination unit (26 in FIG. 1; 26 aand 26 b, respectively, in FIG. 2), and in particular, the maincomponents, transmitted beam first detector (90 in FIG. 1; 90 a and 90b, respectively, in FIG. 2) and transmitted beam second detector (92 inFIG. 1; 92 a and 92 b, respectively, in FIG. 2), in each of the firstand second specific configurations of detection unit (40 in FIG. 1; 40 aand 40 b, respectively, in FIG. 2), and the additional main component,detection unit temperature sensor, TS_(d), (100 in FIG. 1; 100 a and 100b, respectively, in FIG. 2), in the second specific configuration ofdetection unit (40 in FIG. 1; 40 a and 40 b, respectively, in FIG. 2).

Module housing (42 in FIG. 1; 42 a and 42 b, respectively, in FIG. 2)is, preferably, of a square or rectangular geometrical shape, having apreferably tubular or cylindrical opening or hole (to be clearlyunderstood as being present, but not explicitly shown in FIGS. 1 and 2),geometrically appropriate for through passage of tubular or cylindricalshaped transparent housing 62. Module housing (42 in FIG. 1; 42 a and 42b, respectively, in FIG. 2) is constructed from a metallic material, forexample, aluminum, a non-metallic material, a composite material, or acombination thereof, and is configured for enabling operative supportingor holding of transparent housing 62, as well as for enabling operativehousing or holding of selected components of illumination unit (26 inFIG. 1; 26 a and 26 b, respectively, in FIG. 2) and of detection unit(40 in FIG. 1; 40 a and 40 b, respectively, in FIG. 2).

While electro-optically inspecting longitudinally moving rod of material12, temperature changes typically occur in critical regions of modulehousing (42 in FIG. 1; 42 a and 42 b, respectively, in FIG. 2) in eachelectro-optical transmission module (24 in FIG. 1; 24 a and 24 b,respectively, in FIG. 2) of electro-optical inspection devices 10 and60, respectively, particularly in the immediate vicinity of theelectro-optically inspected volumetric segment (34 in FIG. 1; 34 a and34 b, respectively, in FIG. 2) of moving rod of material 12. Magnitudesof such temperature changes may be sufficiently large so as tosignificantly increase noise and error levels during the electro-opticalinspection process, which may translate to meaningful decreases inaccuracy and precision of the results obtained from the electro-opticalinspection process.

For achieving higher sensitivity, signal to noise ratios, accuracy, andprecision, and therefore, overall performance, of the first specificconfiguration of each illumination unit (26 in FIG. 1; 26 a and 26 b,respectively, in FIG. 2), and of each of the first and second specificconfigurations of each detection unit (40 in FIG. 1; 40 a and 40 b,respectively, in FIG. 2), in each electro-optical transmission module(24 in FIG. 1; 24 a and 24 b, respectively, in FIG. 2) ofelectro-optical inspection devices 10 and 60, respectively, preferably,each module housing (42 in FIG. 1; 42 a and 42 b, respectively, in FIG.2) further includes components, in particular, at least onestrategically located module housing temperature sensor, TS_(h), (110 inFIG. 1; 110 a and 110 b, respectively, in FIG. 2) and associatedelectro-optical circuitry, and, sub-steps and procedures, implementedvia corresponding algorithms and software programs, for operatingthereof, for monitoring temperature, typically, in the range of betweenabout 50° C. and 60° C., and compensating for temperature changes incritical regions of module housing (42 in FIG. 1; 42 a and 42 b,respectively, in FIG. 2) in each electro-optical transmission module (24in FIG. 1; 24 a and 24 b, respectively, in FIG. 2) of electro-opticalinspection devices 10 and 60, respectively. Such critical regions ofoperation are particularly in the immediate vicinity of theelectro-optically inspected volumetric segment (34 in FIG. 1; 34 a and34 b, respectively, in FIG. 2) of rod of material 12, longitudinallymoving along optical path 20 within transparent passageway 22 housed bytransparent housing 62, during the electro-optical inspection process.

Module housing temperature sensor, TS_(h), (110 in FIG. 1; 110 a and 110b, respectively, in FIG. 2) generates a module housing temperaturesensor output signal proportional to the sensed temperature in thecritical region of module housing (42 in FIG. 1; 42 a and 42 b,respectively, in FIG. 2), and sends the module housing temperaturesensor output signal to a module housing temperature sensor outputsignal buffer (112 in FIG. 1; 112 a and 112 b, respectively, in FIG. 2).In general, module housing temperature sensor, TS_(h), (110 in FIG. 1;110 a and 110 b, respectively, in FIG. 2) is any appropriately compactor miniature sized and configured temperature sensing device, mechanism,or component, for example, a thermocouple, capable of sensingtemperature, and generating an electrical or electronic signalcorresponding and proportional to the sensed temperature. For processdesign, process control, and reference purposes, calibration data andinformation correlating a range of values of the input sensedtemperature with a corresponding range of values of the correspondingmodule housing temperature sensor output signal, are empiricallydetermined using standardized conditions of operating eachelectro-optical transmission module (24 in FIG. 1; 24 a and 24 b,respectively, in FIG. 2).

Module housing temperature sensor output signal buffer (112 in FIG. 1;112 a and 112 b, respectively, in FIG. 2), in each electro-opticaltransmission module (24 in FIG. 1; 24 a and 24 b, respectively, in FIG.2) of electro-optical inspection devices 10 and 60, respectively,receives the module housing temperature sensor output signal sent frommodule housing temperature sensor, TS_(h), (110 in FIG. 1; 110 a and 110b, respectively, in FIG. 2), and stores the module housing temperaturesensor output signal in the form of a stored module housing temperaturesensor output signal (112′ in FIG. 1; 112′a and 112′b, respectively, inFIG. 2). Stored module housing temperature sensor output signal (112′ inFIG. 1; 112′a and 112′b, respectively, in FIG. 2) is sent to a processcontrol and data analysis unit, for example, process control and dataanalysis unit 120, as shown in FIGS. 1 and 2.

Stored module housing temperature sensor output signal (112′ in FIG. 1;112′a and 112′b, respectively, in FIG. 2) is used for correcting, in atemperature compensative manner, the stored detection unit output signal(106′ in FIG. 1; 106′a and 106′b, respectively, in FIG. 2) which is alsosent to process control and data analysis unit 120, as previouslydescribed above, from detection unit output signal buffer (106 in FIG.1; 106 a and 106 b, respectively, in FIG. 2) of detection unit (40 inFIG. 1; 40 a and 40 b, respectively, in FIG. 2) in each electro-opticaltransmission module (24 in FIG. 1; 24 a and 24 b, respectively, in FIG.2) of electro-optical inspection devices 10 and 60, respectively.

More specifically, process control and data analysis unit 120 compares,and adds or subtracts, in a temperature compensative manner, the valueof the stored module housing temperature sensor output signal (112′ inFIG. 1; 112′a and 112′b, respectively, in FIG. 2), to or from,respectively, the value of the stored detection unit output signal (106′in FIG. 1; 106′a and 106′b, respectively, in FIG. 2), according to themagnitude and the direction or sign (positive or negative) of thetemperature change represented by the stored module housing temperaturesensor output signal (112′ in FIG. 1; 112′a and 112′b, respectively, inFIG. 2), for generating a ‘corrected’ detection unit output signal,which is stored and used by process control and data analysis unit 120for determining the internal properties and characteristics, such asdensity, structure, defects, and impurities, and variabilities thereof,of longitudinally moving rod of material 12. The determined internalproperties and characteristics of moving rod of material 12 are thenuseable by a process control and data analysis unit, for example,process control and data analysis unit 120, for controlling the processof electro-optically inspecting moving rod of material 12, and/or forcontrolling downstream processing of longitudinally moving rod ofmaterial 12.

As previously stated above, the present invention is directed tocommercial applications requiring real time, non-invasive, high speed,high sensitivity, low noise, high accuracy, high precision, temperaturecompensative, and low vibration, measuring and analyzing of internalproperties and characteristics of a continuously or intermittentlylongitudinally moving rod of material, as the rod of material istransported or conveyed during a commercial manufacturing sequence,particularly a manufacturing sequence including quality control and/orquality assurance processes.

Monitoring temperature and compensating for temperature changes incritical regions of operation of the illumination unit (26 in FIG. 1; 26a and 26 b, respectively, in FIG. 2), of the detection unit (40 in FIG.1; 40 a and 40 b, respectively, in FIG. 2), and preferably, also ofmodule housing (42 in FIG. 1; 42 a and 42 b, respectively, in FIG. 2),in the electro-optical transmission module (24 in FIG. 1; 24 a and 24 b,respectively, in FIG. 2) in electro-optical inspection devices 10 and60, of the first and second exemplary specific preferred embodiments,respectively, of the generalized device for electro-optically inspectingand determining internal properties and characteristics of alongitudinally moving rod of material, that is, longitudinally movingrod of material 12, as illustrated in FIGS. 1 and 2, respectively, ofthe present invention, are previously described above.

In general, while electro-optically inspecting a longitudinally movingrod of material, the longitudinally moving rod of material, in general,and the electro-optically inspected section or segment of thelongitudinally moving rod of material, in particular, typicallyvibrates, particularly, in the radial direction. For example, withrespect to implementation of the electro-optical inspection method anddevice of the present invention, as illustratively described above, withreference to FIGS. 1 and 2, while electro-optically inspectinglongitudinally moving rod of material 12, longitudinally moving rod ofmaterial 12, in general, and the electro-optically inspected volumetricsegment (34 in FIG. 1; 34 a and 34 b, respectively, in FIG. 2), inparticular, typically vibrates, particularly, in the radial direction.With reference to reference XYZ coordinate system 50, such radialvibrating occurs in the XY-plane of moving rod of material 12.Magnitudes of such radially directed vibrating may be sufficiently largeso as to significantly increase noise and error levels during theillumination and detection processes, which may translate to meaningfuldecreases in accuracy and precision of the results obtained from theelectro-optical inspection process.

With respect to the generalized electro-optical inspection method of thepresent invention, for achieving higher sensitivity, signal to noiseratios, accuracy, and precision, and therefore, overall performance, ofsteps (a) through (d) in the generalized electro-optical inspectionmethod, preferably, a specific preferred embodiment of the generalizedelectro-optical inspection method further includes sub-steps andprocedures, and components for performing thereof, for preventing,eliminating, or at least reducing, radially directed vibrating oflongitudinally moving rod of material 12, in general, and of theelectro-optically inspected volumetric segment (34 in FIG. 1; 34 a and34 b, respectively, in FIG. 2) of longitudinally moving rod of material12, in particular, during the electro-optical inspection process.

In particular, preferably, following step (a) and preceding step (b) inthe generalized electro-optical inspection method of the presentinvention, as described above, there is inserted the step of generatinga continuous vortical type of flow of gas within and along transparentpassageway 22 by a vortex generating mechanism, preferably, included asa component of rod guiding unit 14, such that the flowing gas rotates asa vortex around optical path 20 and around moving rod of material 12,and flows downstream within and along transparent passageway 22 in thesame longitudinal direction of moving rod of material 12, such that theflowing gas radially impinges upon longitudinally moving rod of material12 within transparent passageway 22. The flowing gas radially impingingupon longitudinally moving rod of material 12 prevents, eliminates, orreduces, radially directed vibrating of longitudinally moving rod ofmaterial 12 during operation of rod guiding unit 14 and during operationof electro-optical transmission module (24 in FIG. 1; 24 a and 24 b,respectively, in FIG. 2), during the electro-optically inspecting anddetermining of the internal properties and characteristics oflongitudinally moving rod of material 12.

With respect to the generalized electro-optical inspection device of thepresent invention, for achieving higher sensitivity, signal to noiseratios, accuracy, and precision, and therefore, overall performance, ofoperation of rod guiding unit 14 and of each electro-opticaltransmission module (24 in FIG. 1; 24 a and 24 b, respectively, in FIG.2) in electro-optical inspection devices 10 and 60, of the first andsecond exemplary specific preferred embodiments, respectively, of thegeneralized device for electro-optically inspecting and determininginternal properties and characteristics of a longitudinally moving rodof material, that is, longitudinally moving rod of material 12, asillustrated in FIGS. 1 and 2, respectively, preferably, rod guiding unit14 further includes components, and, sub-steps and procedures foroperating thereof, for preventing, eliminating, or at least reducing,radially directed vibrating of longitudinally moving rod of material 12,in general, and of the electro-optically inspected volumetric segment 34of longitudinally moving rod of material 12, in particular, during theelectro-optical inspection process.

Accordingly, in a specific, more preferred, configuration of rod guidingunit 14 in electro-optical inspection devices 10 and 60, of the firstand second exemplary specific preferred embodiments, respectively, forelectro-optically inspecting and determining internal properties andcharacteristics of longitudinally moving rod of material 12, asillustrated in FIGS. 1 and 2, respectively, rod guiding unit 14 includesthe main components: (i) transparent housing 62, (ii) rod materialentrance assembly 64, and further includes additional main component:(iii) a vortex generating mechanism 130.

In this specific, more preferred, configuration of rod guiding unit 14in electro-optical inspection devices 10 and 60, structure and functionof transparent housing 62, and of rod material entrance assembly 64,operatively attached or connected to transparent housing 62, are thesame as previously described above.

Vortex generating mechanism 130 is for generating a continuous vorticaltype of flow of gas (indicated in FIGS. 1 and 2 by the alternatingcircularly curved pairs and parallel pairs of solid head referencearrows 132), within and along transparent passageway 22, in particular,extending between rod material entrance area 16 and rod material exitarea 18, of rod guiding unit 14 in each electro-optical inspectiondevice 10 and 60, such that flowing gas 132 rotates as a vortex aroundoptical path 20 and around moving rod of material 12, and flowsdownstream within and along transparent passageway 22 in the samelongitudinal direction of moving rod of material 12 (for example, asshown in FIGS. 1 and 2, in the Z-direction), such that the flowing gasradially impinges upon longitudinally moving rod of material 12 withintransparent passageway 22.

Flowing gas 132 radially impinging upon longitudinally moving rod ofmaterial 12 prevents, eliminates, or reduces, radially directedvibrating of longitudinally moving rod of material 12, in general, andof the electro-optically inspected volumetric segment (34 in FIG. 1; 34a and 34 b, respectively, in FIG. 2) of longitudinally moving rod ofmaterial 12, in particular, during operation of rod guiding unit 14 andduring operation of each electro-optical transmission module (24 in FIG.1; 24 a and 24 b, respectively, in FIG. 2), during the electro-opticallyinspecting and determining of the internal properties andcharacteristics of longitudinally moving rod of material 12.

As shown in FIGS. 1 and 2, in rod guiding unit 14, preferably, vortexgenerating mechanism 130 is operatively connected to rod materialentrance assembly 64, such that the gas, for example, air, used forgenerating the continuous vortical type of flow of gas 132 enters rodguiding unit 14, via rod material entrance assembly 64, in the samegeneral region that moving rod of material 12 enters rod guiding unit 14of each electro-optical inspection device 10 and 60. For example, asshown in FIGS. 1 and 2, vortex generating mechanism 130 is operativelyconnected to a side of rod material entrance assembly 64, such that thegas used for generating the continuous vortical type of flow of gas 132enters rod guiding unit 14, via the side of rod material entranceassembly 64, in the same general region that moving rod of material 12enters rod guiding unit 14 of each electro-optical inspection device 10and 60. More specifically, for example, as also shown in FIGS. 1 and 2,vortex generating mechanism 130 is operatively connected to a side ofrod material entrance assembly 64, such that the gas used for generatingthe continuous vortical type of flow of gas 132 enters rod guiding unit14, via the side of rod material entrance assembly 64, in the samegeneral region that moving rod of material 12 enters rod guiding unit14, and in a direction (for example, in the radial, Y-direction orX-direction) which is orthogonal to the longitudinal direction (forexample, the Z-direction) of movement of moving rod of material 12 whichis longitudinally moved by rod moving unit 5 and longitudinally guidedby rod guiding unit 14.

In rod guiding unit 14, vortex generating mechanism 130 includes themain components: (1) a gas supply 134, (2) a gas intake/output pump 136,and (3) a gas flow directing channel 138.

The gas in gas supply 134 used for generating the continuous vorticaltype of flow of gas 132 is, for example, air, or another gas, forexample, an inert gas such as nitrogen, helium, or argon. The gas isnon-chemically reactive, or at most, minimally or insignificantlychemically reactive, with the material making up moving rod of material12, as well as with the material of construction of transparent housing62, in order to prevent contamination of either of these during theelectro-optical inspection process.

Gas intake/output pump 136 is for taking or pumping in the gas suppliedby gas supply 134, and for outputting or pumping out the taken or pumpedin gas, in the form of a flowing gas. Preferably, the pressure, and thelinear flow velocity, of the gas output or pumped out of gasintake/output pump 136 and, flowing into rod material entrance assembly64 and into transparent housing 62, is on the order of about oneatmosphere above room atmospheric pressure, and on the order of about100 meters per minute, respectively. Such pressure and linear flowvelocity of the flowing gas are also maintained within and alongtransparent passageway 22.

Gas flow directing channel 138, operatively connected to gasintake/output pump 136 and to rod material entrance assembly 64, is fordirecting and channeling the gas taken or pumped in by gas intake/outputpump 136, and for directing and channeling the flowing gas output orpumped out by gas intake/output pump 136 into rod material entranceassembly 64 and into transparent housing 62, such that a continuousvortical type of flow of gas 132 is generated within and alongtransparent passageway 22, in particular, extending between rod materialentrance area 16 and rod material exit area 18, of rod guiding unit 14.Gas flow directing channel 138 is of a variable geometricalconfiguration or form, and is constructed from a metallic material, anon-metallic material, a composite material, or a combination thereof,for enabling operative attachment or connection to transparent housing62, and for enabling directing and channeling of the flowing gas outputor pumped out by gas intake/output pump 136 into rod material entranceassembly 64 and into transparent housing 62.

Accordingly, during operation of vortex generating mechanism 130, aspart of operation of rod guiding unit 14, gas intake/output pump 136takes or pumps in the gas supplied by gas supply 134, as indicated inFIGS. 1 and 2 by 140, and outputs or pumps out the taken or pumped ingas, in the form of a flowing gas. The flowing gas is then directed andchanneled via gas flow directing channel 138 into rod material entranceassembly 64 and into transparent housing 62, such that a continuousvortical type of flow of gas 132 is generated within and alongtransparent passageway 22, in particular, extending between rod materialentrance area 16 and rod material exit area 18, of rod guiding unit 14.The continuous vortical type of flowing gas 132 radially impinging uponlongitudinally moving rod of material 12 prevents, eliminates, orreduces, radially directed vibrating of longitudinally moving rod ofmaterial 12, in general, and of the electro-optically inspectedvolumetric segment (34 in FIG. 1; 34 a and 34 b, respectively, in FIG.2) of longitudinally moving rod of material 12, in particular, duringoperation of rod guiding unit 14 and during operation of eachelectro-optical transmission module (24 in FIG. 1; 24 a and 24 b,respectively, in FIG. 2), during the electro-optically inspecting anddetermining of the internal properties and characteristics oflongitudinally moving rod of material 12. The continuous vortical typeof flow of gas 132 continuously exits transparent passageway 22, inparticular, at rod material exit area 18, of rod guiding unit 14, asindicated by 142.

Accordingly, operation of vortex generating mechanism 130, as part ofoperation of rod guiding unit 14, corresponds to a kind of ‘gas bearing’which assists in producing a smooth and stable longitudinal movement ofmoving rod of material 12 along optical path 20 within transparentpassageway 22, during the entire electro-optical inspection process.

A secondary function of vortex generating mechanism 130, as part ofoperation of rod guiding unit 14, is that of cleaning rod guiding unit14, in general, and that of cleaning transparent passageway 22 withintransparent housing 62, in particular, during the electro-opticalinspection process. The cleaning function of vortex generating mechanism130 is a consequence of the continuous vortical type of flow of gas 132flowing within and along transparent passageway 22, within transparenthousing 62, in particular, from rod material entrance area 16 to rodmaterial exit area 18, of rod guiding unit 14.

The above illustratively described vortex generating mechanism 130, aspart of operation of a rod guiding unit, for example, rod guiding unit14 of the present invention, is generally applicable for preventing,eliminating, or reducing, radially directed vibrating of alongitudinally moving rod of material during electro-opticallyinspecting the longitudinally moving rod of material, and is notspecifically limited to use only with the generalized electro-opticalinspection method and the corresponding generalized electro-opticalinspection device of the present invention. More specifically, the aboveillustratively described vortex generating mechanism 130, is applicablefor use with prior art electro-optical inspection methods, devices, andapparatuses.

Accordingly, the present invention also features a method forpreventing, eliminating, or reducing, radially directed vibrating of alongitudinally moving rod of material during electro-opticallyinspecting the longitudinally moving rod of material, including thesteps of: (a) guiding the longitudinally moving rod of material alongits longitudinal axis by a rod guiding unit, along an optical pathwithin a transparent passageway, where the optical path and thetransparent passageway coaxially extend along the longitudinal axis ofthe longitudinally moving rod of material and pass through anelectro-optical inspection apparatus used for electro-opticallyinspecting the longitudinally moving rod of material; and (b) generatinga continuous vortical type of flow of gas within and along thetransparent passageway by a vortex generating mechanism, such that theflowing gas rotates as a vortex around the optical path and around thelongitudinally moving rod of material, and flows downstream within andalong the transparent passageway in the same longitudinal direction ofthe longitudinally moving rod of material, such that the flowing gasradially impinges upon the longitudinally moving rod of material withinthe transparent passageway. The flowing gas radially impinging upon thelongitudinally moving rod of material prevents, eliminates, or reduces,radially directed vibrating of the longitudinally moving rod of materialduring the electro-optically inspecting the longitudinally moving rod ofmaterial.

Accordingly, the present invention also features a device forpreventing, eliminating, or reducing, radially directed vibrating of alongitudinally moving rod of material during electro-opticallyinspecting the longitudinally moving rod of material, the device being arod guiding unit for guiding the longitudinally moving rod of materialalong its longitudinal axis, along an optical path within a transparentpassageway, where the optical path and the transparent passagewaycoaxially extend along the longitudinal axis of the longitudinallymoving rod of material and pass through an electro-optical inspectionapparatus used for electro-optically inspecting the longitudinallymoving rod of material, where the rod guiding unit includes a vortexgenerating mechanism for generating a continuous vortical type of flowof gas within and along the transparent passageway, such that theflowing gas rotates as a vortex around the optical path and around thelongitudinally moving rod of material, and flows downstream within andalong the transparent passageway in the same longitudinal direction ofthe longitudinally moving rod of material, such that the flowing gasradially impinges upon the longitudinally moving rod of material withinthe transparent passageway. The flowing gas impinging upon thelongitudinally moving rod of material prevents, eliminates, or reduces,radially directed vibrating of the longitudinally moving rod ofmaterial, during the electro-optically inspecting the longitudinallymoving rod of material.

For automatically controlling the process, and analyzing the data, ofthe generalized electro-optical inspection method and correspondingdevice, of the present invention, the present invention further includesprocess control and data analysis steps, sub-steps, and procedures,implemented via corresponding process control and data analysisalgorithms and software programs, and components for performing thereof,in particular, a process control and data analysis unit, such as processcontrol and data analysis unit 120, as shown in FIGS. 1 and 2.

Process control and data analysis unit 120 supplies necessary orappropriate levels of power to each electrically or electronicallyactivated unit, component, mechanism, and element, of electro-opticalinspection devices 10 and 60 (indicated only in FIG. 1, but equallyapplicable in FIG. 2, by the small dotted line and unfilled in circle‘background’ power grid 150, connecting each electrically orelectronically operable unit, component, mechanism, and element, ofelectro-optical inspection devices 10 and, 60 to process control anddata analysis unit 120).

Rod moving unit 5 either includes, or is operatively connected to, a rodmoving unit mechanism 7, which, in addition to being involved in theelectro-mechanics of moving rod of material 12, provides a real time rodmoving unit clock signal 9 to process control and data analysis unit120, that includes data and information about the rate or linear speedat which rod moving unit 5 moves rod of material 12. Such data andinformation is needed for synchronizing both process control and dataanalysis of the electro-optical inspection process. In particular,inspection time of the electro-optically inspected volumetric segment(34 in FIG. 1; 34 a and 34 b, respectively, in FIG. 2) of longitudinallymoving rod of material 12, is a function of both the rate or linearspeed at which rod moving unit 5 moves rod of material 12, and of theactual length of the moving rod of material 12.

Process control and data analysis unit 120 either includes, or isoperatively connected to, a personal computer (PC) workstation 160,useable by an operator or controller of electro-optical inspectiondevices 10 and 16. A process control sub-unit 162 is operativelyconnected to process control and data analysis unit 120, for functioningas an intermediate point between process control and data analysis ofelectro-optical inspection devices 10 and 16, and, process control anddata analysis of further downstream processes, including for example, arod cutting process and a rod segment rejecting process, involvingoperation of a rod cutting unit 164 and a rod segment reject unit 166,respectively, as shown in FIGS. 1 and 2.

Thus, the present invention, as illustratively described and exemplifiedhereinabove, is generally applicable for inspecting and determininginternal properties and characteristics of a variety of different typesof a rod of material, as long as the rod of material exhibits thebehavior that an incident focused beam of electromagnetic radiation,while not altering the rod of material, is affected by and transmittablethrough volumetric segments of the rod of material. For example, but notlimited to, a cigarette rod consisting of processed tobacco inside arolled and sealed tube of cigarette wrapping paper. Moreover, thepresent invention is directed to commercial applications requiring realtime, non-invasive, high speed, high sensitivity, low noise, highaccuracy, high precision, temperature compensative, and low vibration,measuring and analyzing of internal properties and characteristics of acontinuously or intermittently longitudinally moving rod of material, asthe rod of material is transported or conveyed during a commercialmanufacturing sequence, particularly a manufacturing sequence includingquality control and/or quality assurance processes.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention, which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable subcombination.

All publications, patents and patent applications mentioned in thisspecification are herein incorporated in their entirety by referenceinto the specification, to the same extent as if each individualpublication, patent or patent application was specifically andindividually indicated to be incorporated herein by reference. Inaddition, citation or identification of any reference in thisapplication shall not be construed as an admission that such referenceis available as prior art to the present invention.

While the invention has been described in conjunction with specificembodiments and examples thereof, it is evident that many alternatives,modifications and variations will be apparent to those skilled in theart. Accordingly, it is intended to embrace all such alternatives,modifications and variations that fall within the spirit and broad scopeof the appended claims.

1. A method for electro-optically inspecting and determining internalproperties and characteristics of a longitudinally moving rod ofmaterial, comprising the steps of: (a) guiding the longitudinally movingrod of material along its longitudinal axis by a rod guiding unit, alongan optical path within a transparent passageway, said optical path andsaid transparent passageway coaxially extend along said longitudinalaxis of the moving rod of material and pass through an electro-opticaltransmission module; (b) generating a focused beam of electromagneticradiation by an illumination unit of said electro-optical transmissionmodule, such that said focused beam is transmitted through a first sideof said transparent passageway and incident upon the rod of materiallongitudinally moving within said transparent passageway; (c)illuminating a volumetric segment of the longitudinally moving rod ofmaterial by said incident focused beam, such that at least part of saidincident focused beam is affected by and transmitted through saidvolumetric segment and then transmitted through a second side of saidtransparent passageway, for forming a rod material volumetric segmenttransmitted beam; and (d) detecting said rod material volumetric segmenttransmitted beam by a detection unit of said electro-opticaltransmission module, for forming a detected rod material volumetricsegment transmitted beam; and (e) processing and analyzing said focusedbeam of step (b), said incident focused beam of step (c), and said rodmaterial detected volumetric segment transmitted beam of step (d), by aprocess control and data analysis unit, for determining the internalproperties and characteristics of the longitudinally moving rod ofmaterial.
 2. The method of claim 1, wherein said incident focused beamis of electromagnetic radiation selected from the group consisting ofinfrared radiation, visible light, and ultraviolet radiation.
 3. Themethod of claim 1, wherein said incident focused beam is of infraredelectromagnetic radiation having wavelength in a range of between about900 nm and about 1000 nm.
 4. The method of claim 1, wherein saidincident focused beam is of infrared electromagnetic radiation havingwavelength in a range of between about 920 nm and about 970 nm.
 5. Themethod of claim 1, wherein step (b), said generating said focused beamof electromagnetic radiation by said illumination unit includes aprocedure for monitoring temperature and compensating for temperaturechanges in at least one critical region of operation of saidillumination unit.
 6. The method of claim 5, wherein a said criticalregion of operation is in immediate vicinity of said illuminatedvolumetric segment of the rod of material longitudinally moving alongsaid optical path within said transparent passageway during theelectro-optical inspection process.
 7. The method of claim 5, wherein asaid critical region of operation is in immediate vicinity where saidincident focused beam is transmitted through said first side of saidtransparent passageway and incident upon said volumetric segment.
 8. Themethod of claim 5, wherein step (b), said operation of said illuminationunit including said procedure for monitoring temperature andcompensating for temperature changes is based on a temperature changemonitoring and compensating electro-optical feedback loop.
 9. The methodof claim 1, wherein step (d), said detecting said rod materialvolumetric segment transmitted beam by said detection unit furtherincludes a procedure for monitoring temperature and compensating fortemperature changes in at least one critical region of operation of saiddetection unit.
 10. The method of claim 9, wherein a said criticalregion of operation is in immediate vicinity of said illuminatedvolumetric segment of the rod of material longitudinally moving alongsaid optical path within said transparent passageway.
 11. The method ofclaim 9, wherein a said critical region of operation is in immediatevicinity where said rod material volumetric segment transmitted beam istransmitted from said volumetric segment and then transmitted throughsaid second side of said transparent passageway, and then detected andreceived by said detection unit.
 12. The method of claim 9, wherein step(d), operation of said detection unit including said procedure formonitoring temperature and compensating for temperature changes is basedon a temperature change monitoring and compensating electro-opticaldetection circuit.
 13. The method of claim 1, wherein the internalproperties and characteristics are density, structure, defects, andimpurities, and variabilities thereof, of the longitudinally moving rodof material.
 14. The method of claim 1, wherein said electro-opticaltransmission module includes a module housing through which passes saidtransparent passageway within which is said guided longitudinally movingrod of material.
 15. The method of claim 14, further including aprocedure for monitoring temperature and compensating for temperaturechanges in at least one critical region of operation of said modulehousing.
 16. The method of claim 1, further including a procedure forpreventing, eliminating, or reducing, radially directed vibrating of thelongitudinally moving rod of material during electro-opticallyinspecting the longitudinally moving rod of material.
 17. The method ofclaim 16, wherein said procedure includes generating a continuousvortical type of flow of gas within and along said transparentpassageway by a vortex generating mechanism.
 18. The method of claim 17,wherein pressure, and linear flow velocity, of said flow of gas areabout one atmosphere above room atmospheric pressure, and about 100meters per minute, respectively.
 19. The method of claim 17, whereinoperation of said vortex generating mechanism also cleans said rodguiding unit and cleans said transparent passageway during theelectro-optical inspection process.
 20. The method of claim 16, whereinsaid procedure includes generating a continuous vortical type of flow ofgas within and along said transparent passageway by a vortex generatingmechanism, such that said flowing gas rotates as a vortex around saidoptical path and around the longitudinally moving rod of material, andflows downstream within and along said transparent passageway in samelongitudinal direction of the longitudinally moving rod of material,such that said flowing gas radially impinges upon the longitudinallymoving rod of material within said transparent passageway, whereby saidflowing gas radially impinging upon the longitudinally moving rod ofmaterial prevents, eliminates, or reduces, radially directed vibratingof the longitudinally moving rod of material during theelectro-optically inspecting the longitudinally moving rod of material.21. The method of claim 1, further including a procedure for cleaningsaid rod guiding unit and cleaning said transparent passageway duringthe electro-optical inspection process.
 22. The method of claim 21,wherein said procedure includes generating a continuous vortical type offlow of gas within and along said transparent passageway by a vortexgenerating mechanism, whereby said flow of gas cleans said rod guidingunit and cleans said transparent passageway during the electro-opticalinspection process.
 23. The method of claim 1, wherein thelongitudinally moving rod of material is a longitudinally movingcigarette rod.
 24. The method of claim 1, wherein the longitudinallymoving rod of material is a longitudinally moving cigarette rodconsisting of processed tobacco inside a rolled and sealed tube ofcigarette wrapping paper.
 25. The method of claim 1, wherein step (a),said optical path and said transparent passageway coaxially extend alongsaid longitudinal axis of the moving rod of material and pass through aplurality of more than one said electro-optical transmission module. 26.The method of claim 25, wherein each of said plurality of saidelectro-optical transmission modules is positionable at a differentlongitudinal position or location around and along said transparentpassageway within which extends said optical path.
 27. The method ofclaim 25, wherein each of said plurality of said electro-opticaltransmission modules is positionable at a same or different angular,radial, or circumferential, position or location around said transparentpassageway within which extends said optical path.
 28. The method ofclaim 25, wherein longitudinal and angular or circumferential positionsof said plurality of said electro-optical transmission modules, relativeto each other, and relative to said transparent passageway within whichextends said optical path, are spatially staggered or displaced alongsaid optical path, along which the longitudinally moving rod of materialis guided by said rod guiding unit.
 29. The method of claim 25, whereineach said electro-optical transmission module through which pass saidoptical path and said transparent passageway includes a paired saidillumination unit and said detection unit.
 30. The method of claim 29,wherein said paired illumination and detection units of said pluralityof said electro-optical transmission modules are temporally continuouslyor discontinuously activated according to a pre-determined timing orswitching schedule or sequence, while the longitudinally moving rod ofmaterial is continuously or intermittently moving and being guidedthrough said plurality of electro-optical transmission modules.
 31. Themethod of claim 30, wherein said pre-determined timing or switchingschedule or sequence is effected via applying a synchronous orasynchronous on/off switching schedule or sequence for operating saidpaired illumination and detection units.
 32. A method for preventing,eliminating, or reducing, radially directed vibrating of alongitudinally moving rod of material during electro-opticallyinspecting the longitudinally moving rod of material, comprising thesteps of: (a) guiding the longitudinally moving rod of material alongits longitudinal axis by a rod guiding unit, along an optical pathwithin a transparent passageway, said optical path and said transparentpassageway coaxially extend along said longitudinal axis of thelongitudinally moving rod of material and pass through anelectro-optical inspection apparatus used for electro-opticallyinspecting the longitudinally moving rod of material; and (b) generatinga continuous vortical type of flow of gas within and along saidtransparent passageway by a vortex generating mechanism, such that saidflowing gas rotates as a vortex around said optical path and around thelongitudinally moving rod of material, and flows downstream within andalong said transparent passageway in same longitudinal direction of thelongitudinally moving rod of material, such that said flowing gasradially impinges upon the longitudinally moving rod of material withinsaid transparent passageway; whereby said flowing gas radially impingingupon the longitudinally moving rod of material prevents, eliminates, orreduces, radially directed vibrating of the longitudinally moving rod ofmaterial during the electro-optically inspecting the longitudinallymoving rod of material.
 33. The method of claim 32, wherein pressure,and linear flow velocity, of said flow of gas are about one atmosphereabove room atmospheric pressure, and about 100 meters per minute,respectively.
 34. A device for electro-optically inspecting anddetermining internal properties and characteristics of a longitudinallymoving rod of material, comprising: (a) a rod guiding unit for guidingthe longitudinally moving rod of material along its longitudinal axis,along an optical path within a transparent passageway, said optical pathand said transparent passageway coaxially extend along said longitudinalaxis of the moving rod of material; and (b) an electro-opticaltransmission module through which pass said optical path and saidtransparent passageway, said electro-optical transmission moduleincludes: (i) an illumination unit for generating a focused beam ofelectromagnetic radiation, such that said focused beam is transmittedthrough a first side of said transparent passageway and incident uponthe rod of material longitudinally moving within said transparentpassageway, said incident focused beam illuminates a volumetric segmentof the longitudinally moving rod of material, such that at least part ofsaid incident focused beam is transmitted through said volumetricsegment and through a second side of said transparent passageway, forforming a rod material volumetric segment transmitted beam; and (ii) adetection unit for detecting said rod material volumetric segmenttransmitted beam, for forming a detected rod material volumetric segmenttransmitted beam useable for determining the internal properties andcharacteristics of the longitudinally moving rod of material.
 35. Thedevice of claim 34, wherein said rod guiding unit includes a transparenthousing, for housing, holding, or confining, said transparent passagewaywithin which is said optical path, along which is guided thelongitudinally moving rod of material.
 36. The device of claim 35,wherein said transparent housing is of a hollow tubular or cylindricalgeometrical shape, and is constructed from an optically transparentmaterial.
 37. The device of claim 34, wherein said illumination unitincludes an electromagnetic radiation beam source, said electromagneticradiation beam source is of structure and functions according to eitherlight emitting diode technology, or fiber optic technology.
 38. Thedevice of claim 34, wherein said incident focused beam is ofelectromagnetic radiation selected from the group consisting of infraredradiation, visible light, and ultraviolet radiation.
 39. The device ofclaim 34, wherein said incident focused beam is of infraredelectromagnetic radiation having wavelength in a range of between about900 nm and about 1000 nm.
 40. The device of claim 34, wherein saidincident focused beam is of infrared electromagnetic radiation havingwavelength in a range of between about 920 nm and about 970 nm.
 41. Thedevice of claim 34, wherein said illumination unit includes componentsand is operated by a procedure for monitoring temperature andcompensating for temperature changes in at least one critical region ofoperation of said illumination unit.
 42. The device of claim 41, whereinsaid components of said illumination unit for said monitoringtemperature and said compensating for said temperature changes include:a polarizing beam splitter, an optical feedback reference beam detector,an optical feedback reference beam signal amplifier, an illuminationunit temperature sensor, an illumination unit temperature sensor signalamplifier, an illumination unit signal comparator, a proportionalintegrated regulator, a current regulator, and illumination unitelectro-optical feedback loop component connections and linkages. 43.The device of claim 41, wherein a said critical region of operation isin immediate vicinity of said illuminated volumetric segment of the rodof material longitudinally moving along said optical path within saidtransparent passageway during the electro-optical inspection process.44. The device of claim 41, wherein a said critical region of operationis in immediate vicinity where said incident focused beam is transmittedthrough said first side of said transparent passageway and incident uponsaid volumetric segment.
 45. The device of claim 41, wherein saidoperation of said illumination unit including said components and saidprocedure for monitoring temperature and compensating for temperaturechanges is based on a temperature change monitoring and compensatingelectro-optical feedback loop.
 46. The device of claim 34, wherein saiddetection unit includes at least one transmitted beam detector, eachsaid transmitted beam detector is of structure and functions as a lightreceiving type of device selected from the group consisting of aphototransistor, a photosensitive transducer, a fiber optic conductor orguide, and a photoelectric element.
 47. The device of claim 34, whereinsaid detection unit includes components and is operated by a procedurefor monitoring temperature and compensating for temperature changes inat least one critical region of operation of said detection unit. 48.The device of claim 47, wherein said components of said detection unitfor said monitoring temperature and said compensating for saidtemperature changes include: a detection unit temperature sensor, adetection unit temperature sensor signal amplifier, and a detection unitsignal comparator.
 49. The device of claim 47, wherein a said criticalregion of operation is in immediate vicinity of said illuminatedvolumetric segment of the rod of material longitudinally moving alongsaid optical path within said transparent passageway.
 50. The device ofclaim 47, wherein a said critical region of operation is in immediatevicinity where said rod material volumetric segment transmitted beam istransmitted from said volumetric segment and then transmitted throughsaid second side of said transparent passageway, and then detected andreceived by said detection unit.
 51. The device of claim 47, whereinsaid operation of said detection unit including said components and saidprocedure for monitoring temperature and compensating for temperaturechanges is based on a temperature change monitoring and compensatingelectro-optical detection circuit.
 52. The device of claim 34, whereinthe internal properties and characteristics are density, structure,defects, and impurities, and variabilities thereof, of thelongitudinally moving rod of material.
 53. The device of claim 34,wherein said electro-optical transmission module includes a modulehousing through which passes said transparent passageway within which issaid guided longitudinally moving rod of material.
 54. The device ofclaim 53, wherein said module housing includes components and isoperated by a procedure for monitoring temperature and compensating fortemperature changes in at least one critical region of operation of saidmodule housing.
 55. The device of claim 54, wherein said components ofsaid module housing for said monitoring temperature and saidcompensating for said temperature changes include: a module housingtemperature sensor, and associated electro-optical circuitry.
 56. Thedevice of claim 34, further including components for preventing,eliminating, or reducing, radially directed vibrating of thelongitudinally moving rod of material during electro-opticallyinspecting the longitudinally moving rod of material.
 57. The device ofclaim 56, wherein said components include: a vortex generatingmechanism, for generating a continuous vortical type of flow of gaswithin and along said transparent passageway.
 58. The device of claim57, wherein pressure, and linear flow velocity, of said flow of gas areabout one atmosphere above room atmospheric pressure, and about 100meters per minute, respectively.
 59. The device of claim 57, whereinoperation of said vortex generating mechanism also cleans said rodguiding unit and cleans said transparent passageway during theelectro-optical inspection process.
 60. The device of claim 56, whereinsaid components include: a vortex generating mechanism, for generating acontinuous vortical type of flow of gas within and along saidtransparent passageway, such that said flowing gas rotates as a vortexaround said optical path and around the longitudinally moving rod ofmaterial, and flows downstream within and along said transparentpassageway in same longitudinal direction of the longitudinally movingrod of material, such that said flowing gas radially impinges upon thelongitudinally moving rod of material within said transparentpassageway, whereby said flowing gas radially impinging upon thelongitudinally moving rod of material prevents, eliminates, or reduces,radially directed vibrating of the longitudinally moving rod of materialduring the electro-optically inspecting the longitudinally moving rod ofmaterial.
 61. The device of claim 34, further including components forcleaning said rod guiding unit and cleaning said transparent passagewayduring the electro-optical inspection process.
 62. The device of claim61, wherein said components include: a vortex generating mechanism, forgenerating a continuous vortical type of flow of gas within and alongsaid transparent passageway, whereby said flow of gas cleans said rodguiding unit and cleans said transparent passageway during theelectro-optical inspection process.
 63. The device of claim 34, whereinthe longitudinally moving rod of material is a longitudinally movingcigarette rod.
 64. The device of claim 34, wherein the longitudinallymoving rod of material is a longitudinally moving cigarette rodconsisting of processed tobacco inside a rolled and sealed tube ofcigarette wrapping paper.
 65. The device of claim 34, wherein saidoptical path and said transparent passageway coaxially extend along saidlongitudinal axis of the moving rod of material and pass through aplurality of more than one said electro-optical transmission module. 66.The device of claim 65, wherein each of said plurality of saidelectro-optical transmission modules is positionable at a differentlongitudinal position or location around and along said transparentpassageway within which extends said optical path.
 67. The device ofclaim 65, wherein each of said plurality of said electro-opticaltransmission modules is positionable at a same or different angular,radial, or circumferential, position or location around said transparentpassageway within which extends said optical path.
 68. The device ofclaim 65, wherein longitudinal and angular or circumferential positionsof said plurality of said electro-optical transmission modules, relativeto each other, and relative to said transparent passageway within whichextends said optical path, are spatially staggered or displaced alongsaid optical path, along which the longitudinally moving rod of materialis guided by said rod guiding unit.
 69. The device of claim 65, whereineach said electro-optical transmission module through which pass saidoptical path and said transparent passageway includes a paired saidillumination unit and said detection unit.
 70. The device of claim 69,wherein said paired illumination and detection units of said pluralityof said electro-optical transmission modules are temporally continuouslyor discontinuously activated according to a pre-determined timing orswitching schedule or sequence, while the longitudinally moving rod ofmaterial is continuously or intermittently moving and being guidedthrough said plurality of electro-optical transmission modules.
 71. Thedevice of claim 70, wherein said pre-determined timing or switchingschedule or sequence is effected via applying a synchronous orasynchronous on/off switching schedule or sequence for operating saidpaired illumination and detection units.
 72. A device for preventing,eliminating, or reducing, radially directed vibrating of alongitudinally moving rod of material during electro-opticallyinspecting the longitudinally moving rod of material, comprising: a rodguiding unit for guiding the longitudinally moving rod of material alongits longitudinal axis, along an optical path within a transparentpassageway, said optical path and said transparent passageway coaxiallyextend along said longitudinal axis of the longitudinally moving rod ofmaterial and pass through an electro-optical inspection apparatus usedfor electro-optically inspecting the longitudinally moving rod ofmaterial, said rod guiding unit includes a vortex generating mechanismfor generating a continuous vortical type of flow of gas within andalong said transparent passageway, such that said flowing gas rotates asa vortex around said optical path and around the longitudinally movingrod of material, and flows downstream within and along said transparentpassageway in same longitudinal direction of the longitudinally movingrod of material, such that said flowing gas radially impinges upon thelongitudinally moving rod of material within said transparentpassageway, whereby said flowing gas impinging upon the longitudinallymoving rod of material prevents, eliminates, or reduces, radiallydirected vibrating of the longitudinally moving rod of material, duringthe electro-optically inspecting the longitudinally moving rod ofmaterial.
 73. The device of claim 72, wherein pressure, and linear flowvelocity, of said flow of gas are about one atmosphere above roomatmospheric pressure, and about 100 meters per minute, respectively.